BNDX Vanguard Total International Bond

Fund Summary

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Examples

The following examples are intended to help you compare the cost of investing in the Fund's Investor Shares or Admiral Shares with the cost of investing in other mutual funds. They illustrate the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. These examples assume that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense examples, reduce the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 26% of the average value of its portfolio.

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other issuers represented in the Index. The Index methodology is not designed to satisfy the diversification requirements of the Investment Company Act of 1940. The Fund will attempt to hedge its foreign currency exposure, primarily through the use of foreign currency exchange forward contracts, in order to correlate to the returns of the Index, which is U.S. dollar hedged. Such hedging is intended to minimize the currency risk associated with investment in bonds denominated in currencies other than the U.S. dollar.

The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund's investments will be selected through the sampling process and, under normal circumstances, at least 80% of the Fund's assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of October 31, 2019, the dollar-weighted average maturity of the Index was 9.9 years.

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•Credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. Credit risk should be relatively low for the Fund because it purchases only bonds that are of investment-grade quality.

•Call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond's call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. Such redemptions and subsequent reinvestments would also increase the Fund's portfolio turnover rate. Call risk should be low for the Fund because it invests only a small portion of its assets in callable bonds.

•Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

•Currency risk and currency hedging risk. The Fund seeks to mimic the performance of foreign bonds without regard to currency exchange rate fluctuations. To accomplish this goal, the Fund attempts to offset, or hedge, its foreign currency exposure by entering into currency hedging transactions, primarily through the use of foreign currency exchange forward contracts (a type of derivative). However, it generally is not possible to perfectly hedge the Fund's foreign currency exposure. The Fund will decline in value if it underhedges a currency that has weakened or overhedges a currency that has strengthened relative to the U.S. dollar. In addition, the Fund will incur expenses to hedge its foreign currency exposure. By entering into currency hedging transactions, the Fund may eliminate any chance to benefit from favorable fluctuations in relevant currency exchange rates. Currency risk and currency hedging risk for the Fund is low. The Fund's use of foreign currency exchange forward contracts also subjects the Fund to counterparty risk, which is the chance that the counterparty to a currency forward contract with the Fund will be unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

•Derivatives risk. The Fund may invest in derivatives, which may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

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Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. Because the eligibility requirements for the Fund's Admiral Shares were recently changed, annual total returns for the Fund's Admiral Shares are relevant for most investors. Accordingly, the information presented in the bar chart reflects the performance of the Fund's Admiral Shares. The bar chart shows how the performance of the Fund's Admiral Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the share classes presented compare with those of the Fund's target index, which has investment characteristics similar to those of the Fund. Keep in mind that the Fund's past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

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During the periods shown in the bar chart, the highest return for a calendar quarter was 3.44% (quarter ended March 31, 2016), and the lowest return for a quarter was –2.92% (quarter ended June 30, 2015).

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Average Annual Total Returns for Periods Ended December 31, 2019

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are shown only for the Admiral Shares and may differ for each share class. After-tax returns are not relevant for a shareholder who holds fund shares in a tax- deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

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Purchase and Sale of Fund Shares

You may purchase or redeem shares online through our website (vanguard.com), by mail (The Vanguard Group, P.O. Box 1110, Valley Forge, PA 19482-1110), or by telephone (800-662-2739). The minimum investment amount required to open and maintain a Fund account for Admiral Shares is $3,000. The minimum investment amount required to add to an existing Fund account is generally $1. Investor Shares are generally available only to Vanguard funds that operate as funds of funds and to certain retirement plan clients that receive recordkeeping services from Vanguard. Financial intermediaries, institutional clients, and Vanguard-advised clients should contact Vanguard for information on special eligibility rules that may apply to them regarding Admiral Shares. If you are investing through an intermediary, please contact that firm directly for more information regarding your eligibility. If you are investing through an employer- sponsored retirement or savings plan, your plan administrator or your benefits office can provide you with detailed information on how you can invest through your plan.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gain. If you are investing through a tax-advantaged account, such as an IRA or an employer- sponsored retirement or savings plan, special tax rules apply.

Payments to Financial Intermediaries

The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.

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Investing in Index Funds

What Is Indexing?

Indexing is an investment strategy for tracking the performance of a specified market benchmark, or "index." An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market.

There are many types of indexes. Some represent entire markets—such as the U.S. stock market or the U.S. bond market. Other indexes cover market segments—such as small-capitalization stocks or short-term bonds. One cannot invest directly in an index.

The index sponsor determines the securities to include in the index, the weighting of each security in the index, and the appropriate time to make changes to the composition of the index. Generally, the index sponsor does not provide any warranty, or accept any liability, with respect to the quality, accuracy, or completeness of either the target index or its related data. Errors made by the index sponsor may occur from time to time and may not be identified by the index sponsor for a period of time or at all. Vanguard does not provide any warranty or guarantee against such errors. Therefore, the gains, losses, or costs associated with the index sponsor's errors will generally be borne by the index fund and its shareholders.

An index fund seeks to hold all, or a representative sample, of the securities that make up its target index. Index funds attempt to mirror the performance of the target index, for better or worse. However, an index fund generally does not perform exactly like its target index. For example, index funds have operating expenses and transaction costs. Market indexes do not, and therefore they will usually have a slight performance advantage over funds that track them. The ability of an index fund to match its performance to that of its target index can also be impacted by, among other things, the timing and size of cash flows and the size of the fund. Market disruptions and regulatory restrictions could also have an adverse effect on a fund's ability to adjust its exposure to the required levels in order to track the index.

Index funds typically have the following characteristics:

•Variety of investments. Index funds generally invest in the securities of a variety of companies, industries, and government entities.

•Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.

•Low cost. Index funds are generally inexpensive to run compared with actively managed funds. They have low or no research costs and typically keep trading activity—and thus dealer markups and other transaction costs—to a minimum compared with actively managed funds.

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More on the Fund

This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main principles of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance

for fluctuations in the securities markets. Look for this symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

This prospectus offers the Fund's Investor Shares and Admiral Shares. A separate prospectus offers the Fund's Institutional Shares, which are generally for investors who invest a minimum of $5 million. Another prospectus offers Institutional Select Shares, which are generally for investors who invest a minimum of $3 billion. In addition, the Fund issues ETF Shares (an exchange-traded class of shares), which are also offered through a separate prospectus.

All share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses;

as a result, their investment returns will differ.

Plain Talk About Fund Expenses

All mutual funds have operating expenses. These expenses, which are deducted from a fund's gross income, are expressed as a percentage of the net assets of the fund. Assuming that operating expenses remain as stated in the Fees and Expenses section, Vanguard Total International Bond Index Fund's expense ratios would be as follows: for Investor Shares, 0.13%, or $1.30 per $1,000 of average net assets; for Admiral Shares, 0.11%, or $1.10 per $1,000 of average net assets. The average expense ratio for international income funds in 2018 was 0.93%, or $9.30 per $1,000 of average net assets (derived from data provided by Lipper, a Thomson Reuters Company, which reports on the mutual fund industry).

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Plain Talk About Costs of Investing

Costs are an important consideration in choosing a mutual fund. That is because you, as a shareholder, pay a proportionate share of the costs of operating a fund and any transaction costs incurred when the fund buys or sells securities. These costs can erode a substantial portion of the gross income or the capital appreciation a fund achieves. Even seemingly small differences in expenses can, over time, have a dramatic effect on a fund's performance.

The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its objective. The Fund's board of trustees, which oversees the Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Note that the Fund's investment objective is not fundamental and may be changed without a shareholder vote. The Fund's policy of investing at least 80% of its assets in securities that are held in its target index may be changed only upon 60 days' notice to shareholders.

Market Exposure

The Fund is subject to interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests in a geographically diverse mix of short-, intermediate-, and long-term bonds.

Although bonds are often thought to be less risky than stocks, there have been periods when bond prices have fallen significantly because of rising interest rates. For instance, prices of U.S. long-term bonds fell by almost 48% between December 1976 and September 1981. Note that over comparable periods of time, the prices of foreign bonds and U.S. bonds may increase or decrease by different amounts, and in some cases may move in opposite directions.

To illustrate the relationship between bond prices and interest rates, the following table shows the effect of a 1% and a 2% change (both up and down) in interest rates on the values of three noncallable bonds (i.e., bonds that cannot be redeemed by the issuer) of different maturities, each with a face value of $1,000.

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1 Assuming a 4% coupon rate.

These figures are for illustration only; you should not regard them as an indication of future performance of foreign bonds generally or the Fund in particular.

Plain Talk About Bonds and Interest Rates

As a rule, when interest rates rise, bond prices fall. The opposite is also true: Bond prices go up when interest rates fall. Why do bond prices and interest rates move in opposite directions? Let's assume that you hold a bond offering a 4% yield. A year later, interest rates are on the rise and bonds of comparable quality and maturity are offered with a 5% yield. With higher-yielding bonds available, you would have trouble selling your 4% bond for the price you paid—you would probably have to lower your asking price. On the other hand, if interest rates were falling and 3% bonds were being offered, you should be able to sell your 4% bond for more than you paid.

Changes in interest rates can affect bond income as well as bond prices.

The Fund is subject to income risk, which is the chance that the Fund's income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest new cash flow and cash from maturing bonds in lower-yielding bonds. Income risk should be moderate for the Fund because it invests in a diverse mix of short-, intermediate-, and long-term bonds, so investors should expect the Fund's monthly income to fluctuate.

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Plain Talk About Bond Maturities

A bond is issued with a specific maturity date—the date when the issuer must pay back the bond's principal (face value). Bond maturities range from less than 1 year to more than 30 years. Typically, the longer a bond's maturity, the more price risk you, as a bond investor, will face as interest rates rise—but also the higher the potential yield you could receive. Longer-term bonds are more suitable for investors willing to take a greater risk of price fluctuations to get higher and more stable interest income. Shorter-term bond investors should be willing to accept lower yields and greater income variability in return for less fluctuation in the value of their investment. The stated maturity of a bond may differ from the effective maturity of a bond, which takes into consideration that an action such as a call or refunding may cause bonds to be repaid before their stated maturity dates.

Although falling interest rates tend to strengthen bond prices, they can cause other problems for bond fund investors—bond calls and prepayments.

The Fund is subject to call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond's call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. Such redemptions and subsequent reinvestments would also increase the Fund's portfolio turnover rate.

Because the Fund invests only a small portion of its assets in callable bonds, call risk should be low for the Fund.

The Fund is subject to credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. Credit risk should be relatively low for the Fund because it purchases only bonds that are of investment-grade quality.

Although the Fund purchases only investment-grade bonds, a bond held by the Fund may be downgraded, causing the Fund to hold securities below investment-grade. If a bond is downgraded below investment-grade, the Fund will generally attempt to sell the bond within a reasonable period of time. If the Fund determines that the bond cannot be sold at a reasonable price, the Fund may hold the bond until a reasonable price for the bond may be obtained.

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Plain Talk About Credit Quality

A bond's credit quality rating is an assessment of the issuer's ability to pay interest on the bond and, ultimately, to repay the principal. The lower the credit quality, the greater the perceived chance that the bond issuer will default, or fail to meet its payment obligations. All things being equal, the lower a bond's credit quality, the higher its yield should be to compensate investors for assuming additional risk.

The Fund is subject to country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign companies, governments, or government agencies. Because the Fund may invest a large portion of its assets in bonds of issuers located in a particular country or region, the Fund's performance may be hurt disproportionately by the poor performance of its investments in that area. Country/regional risk for the Fund is high.

As of October 31, 2019, the target index for the Fund held a substantial percentage of its assets in bonds of issuers located in a small number of markets, as shown in the following table:

Bloomberg Barclays Global Aggregate ex-USD

Float Adjusted RIC Capped Index (USD Hedged)

The Fund is subject to nondiversification risk, which is the chance that the Fund's performance may be hurt disproportionately by the poor performance of bonds issued by just a few issuers or even a single issuer. The Fund is considered nondiversified, which means that it may invest a significant percentage of its assets in bonds issued by a small number of issuers as compared with diversified mutual funds.

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As of October 31, 2019, the target index for the Fund held a substantial percentage of its assets in bonds of a small number of issuers, as shown in the following table:

Bloomberg Barclays Global Aggregate ex-USD

Float Adjusted RIC Capped Index (USD Hedged)

The Fund is subject to currency risk and currency hedging risk. The Fund seeks to mimic the performance of foreign bonds without regard to currency exchange rate fluctuations. To accomplish this goal, the Fund attempts to offset, or hedge, its foreign currency exposure by entering into currency hedging transactions, primarily through the use of foreign currency exchange forward contracts (a type of derivative). However, it generally is not possible to perfectly hedge the Fund's foreign currency exposure. The Fund will decline in value if it underhedges a currency that has weakened or overhedges a currency that has strengthened relative to the U.S. dollar. In addition, the Fund will incur expenses to hedge its foreign currency exposure. By entering into currency hedging transactions, the Fund may eliminate any chance to benefit from favorable fluctuations in relevant currency exchange rates. Currency risk and currency hedging risk for the Fund is low. The Fund's use of foreign currency exchange forward contracts also subjects the Fund to counterparty risk, which is the chance that the counterparty to a currency forward contract with the Fund will be unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

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Plain Talk About International Investing

U.S. investors who invest in foreign securities will encounter risks not typically associated with U.S. companies because foreign stock and bond markets operate differently from the U.S. markets. For instance, foreign companies and governments may not be subject to the same or similar accounting, auditing, legal, tax, and financial reporting standards and practices as U.S. companies and the U.S. government, and their stocks and bonds may not be as liquid as those of similar U.S. entities. In addition, foreign stock exchanges, brokers, companies, bond markets, and dealers may be subject to less government supervision and regulation than their counterparts in the United States. These factors, among others, could negatively affect the returns U.S. investors receive from foreign investments.

Security Selection

Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all, or substantially all, of the bonds held in its target index—which is an indexing strategy called "replication"—the Fund uses index "sampling" techniques to select securities. Using computer programs, the Fund's advisor generally selects a representative sample of securities that approximates the full target index in terms of key risk factors and other characteristics. These factors include country of origin, duration, cash flow, credit quality, and callability of the underlying bonds. Because the Fund does not hold all of the securities in its target index, some of the securities (and issuers) that are held will likely be overweighted (or underweighted) compared with the target index.

The Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

The number of bonds held by the Fund and the number of bonds in the Fund's target index were 6,117 and 10,906, respectively, as of October 31, 2019.

Types of bonds. The Fund seeks to track the investment performance of the Bloomberg Barclays Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged). This Index provides a broad-based measure of the global, investment-grade, fixed-rate debt markets. The Index includes government, government agency, corporate, and securitized non-U.S. investment-grade fixed income investments, all issued in currencies other than the U.S. dollar and with maturities of more than one year. The Index is capped to comply with investment company diversification standards of the Internal Revenue Code, which state that, at the close of each fiscal

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quarter, a fund's (1) exposure to any particular bond issuer may not exceed 25% of the fund's assets and (2) aggregate exposure to issuers that individually constitute 5% or more of the fund may not exceed 50% of the fund's assets. To help enforce these limits, if the Index, on the last business day of any month, were to have greater than 20% exposure to any particular bond issuer, or greater than 48% aggregate exposure to issuers that individually constitute 5% or more of the Index, then the excess would be reallocated to bonds of other issuers represented in the Index. Notwithstanding the fact that the Index is capped, exposure of the Index or the Fund to a particular bond issuer may exceed 25%, and issuers that individually constitute 5% or more of the Index or the Fund may, in the aggregate, constitute more than 50% of the Index or the Fund on any day during the month because of currency and/or price movements.

The Fund will attempt to hedge its foreign currency exposure, primarily through the use of foreign currency exchange forward contracts, in order to correlate to the returns of the Index, which is U.S. dollar hedged. Such hedging is intended to minimize the currency risk associated with investment in bonds denominated in currencies other than the U.S. dollar. Local currency bonds are bonds denominated in the local currency of a non-U.S. country. They can be issued by foreign governments, government agencies, and corporations. To the extent that the Fund owns local currency bonds and hedges its foreign currency exposure, it is subject to currency hedging risk. Currency hedging risk should be low for the Fund. All of the bonds held by the Fund will be local currency bonds.

To the extent that the Fund enters into currency hedging transactions, the Fund is subject to counterparty risk. Counterparty risk is the chance that the counterparty to a currency forward contract with the Fund is unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

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Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index, or a reference rate. The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

•Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

•Add value when these instruments are attractively priced.

•Adjust sensitivity to changes in interest rates.

•Hedge foreign currency exposure.

The Fund's derivative investments may include fixed income futures contracts, fixed income options, interest rate swaps, total return swaps, credit default swaps, or other derivatives. Losses (or gains) involving futures contracts can sometimes be substantial—in part because a relatively small price movement in a futures contract may result in an immediate and substantial loss (or gain) for a fund. Similar risks exist for other types of derivatives.

The Fund will enter into foreign currency exchange forward contracts, which are a type of derivative, in order to hedge its foreign currency exposure. A foreign currency exchange forward contract is an agreement to buy or sell a currency at a specific price on a specific date, usually 30, 60, or 90 days in the future. These contracts will be used in an effort to offset any changes in the dollar value of foreign bonds attributable to changes in the value of the bonds' local currencies relative to the U.S. dollar. Although such contracts can protect the Fund from unfavorable fluctuations in currency exchange rates, they also reduce or eliminate any chance for the Fund to benefit from favorable exchange rate fluctuations. Notably, foreign currency exchange forward contracts do not prevent the Fund's securities from falling in value for reasons unrelated to currency exchange rates, such as interest rate increases and credit downgrades.

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Plain Talk About Derivatives

Derivatives can take many forms. Some forms of derivatives—such as exchange- traded futures and options on securities, commodities, or indexes—have been trading on regulated exchanges for decades. These types of derivatives are standardized contracts that can easily be bought and sold and whose market values are determined and published daily. On the other hand, non-exchange- traded derivatives—such as certain swap agreements and foreign currency exchange forward contracts—tend to be more specialized or complex and may be more difficult to accurately value.

The Fund may invest a small portion of its assets in fixed income futures, which are a type of derivative, and/or shares of exchange-traded funds (ETFs). These fixed income futures and ETFs typically provide returns similar to those of the bonds listed in the index, or in a subset of the index, the Fund seeks to track. The Fund may purchase futures or ETFs when doing so will reduce the Fund's transaction costs, facilitate cash management, mitigate risk, or have the potential to add value because the instruments are favorably priced. Vanguard receives no additional revenue from Fund assets invested in ETF Shares of other Vanguard funds. Fund assets invested in ETF Shares are excluded when allocating to the Fund its share of the costs of Vanguard operations.

Cash Management

The Fund's daily cash balance may be invested in Vanguard Market Liquidity Fund and/or Vanguard Municipal Cash Management Fund (each, a CMT Fund), which are low-cost money market funds. When investing in a CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a CMT Fund.

Methods Used to Meet Redemption Requests

Under normal circumstances, the Fund typically expects to meet redemptions with positive cash flows. When this is not an option, the Fund seeks to maintain its risk exposure by selling a cross section of the Fund's holdings to meet redemptions, while also factoring in transaction costs. Additionally, the Fund may work with larger clients to implement their redemptions in a manner that is least disruptive to the portfolio; see "Potentially disruptive redemptions" under Redeeming Shares in the Investing With Vanguard section.

Under certain circumstances, including under stressed market conditions, there are additional tools that the Fund may use in order to meet redemptions, including advancing the settlement of market trades with counterparties to match investor

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redemption payments or delaying settlement of an investor's transaction to match trade settlement within regulatory requirements. The Fund may also suspend payment of redemption proceeds for up to seven days; see "Emergency circumstances" under Redeeming Shares in the Investing With Vanguard section. Additionally under these unusual circumstances, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility or through a bank line-of-credit, including a joint committed credit facility, in order to meet redemption requests.

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund's best interest, so long as the strategy or policy employed is consistent with the Fund's investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange- traded funds that are consistent with the Fund's investment objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately.

Frequent Trading or Market-Timing

Background. Some investors try to profit from strategies involving frequent trading of mutual fund shares, such as market-timing. For funds holding foreign securities, investors may try to take advantage of an anticipated difference between the price of the fund's shares and price movements in overseas markets, a practice also known as time-zone arbitrage. Investors also may try to engage in frequent trading of funds holding investments such as small-cap stocks and high-yield bonds. As money is shifted into and out of a fund by a shareholder engaging in frequent trading, the fund incurs costs for buying and selling securities, resulting in increased brokerage and administrative costs. These costs are borne by all fund shareholders, including the long-term investors who do not generate the costs. In addition, frequent trading may interfere with an advisor's ability to efficiently manage the fund.

Policies to address frequent trading. The Vanguard funds (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation- Protected Securities Index Fund) do not knowingly accommodate frequent trading. The board of trustees of each Vanguard fund (other than money market funds and short- term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) has adopted policies and procedures reasonably designed to detect and discourage frequent trading and, in some cases, to compensate the fund for the costs associated with it. These policies and procedures do not apply to ETF Shares because frequent trading in ETF Shares generally does not disrupt portfolio management or otherwise harm fund shareholders. Although there is no assurance that Vanguard will

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be able to detect or prevent frequent trading or market-timing in all circumstances, the following policies have been adopted to address these issues:

•Each Vanguard fund reserves the right to reject any purchase request—including exchanges from other Vanguard funds—without notice and regardless of size. For example, a purchase request could be rejected because the investor has a history of frequent trading or if Vanguard determines that such purchase may negatively affect a fund's operation or performance.

•Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) generally prohibits, except as otherwise noted in the Investing With Vanguard section, an investor's purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account.

•Certain Vanguard funds charge shareholders purchase and/or redemption fees on transactions.

See the Investing With Vanguard section of this prospectus for further details on Vanguard's transaction policies.

Each Vanguard fund (other than retail and government money market funds), in determining its net asset value, will use fair-value pricing when appropriate, as described in the Share Price section. Fair-value pricing may reduce or eliminate the profitability of certain frequent-trading strategies.

Do not invest with Vanguard if you are a market-timer.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests from shareholders of conventional (not exchange- traded) shares or to changes in the composition of its target index or in an effort to manage the fund's duration. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A turnover rate of 100%, for example, would mean that the Fund had sold and replaced securities valued at 100% of its net assets within a one-year period. In general, the greater the turnover rate, the greater the impact transaction costs will have on a fund's return. Also, funds with high turnover rates may be more likely to generate capital gains, including short-term capital gains, that must be distributed to shareholders and will be taxable to shareholders investing through a taxable account.

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The Fund and Vanguard

The Fund is a member of The Vanguard Group, a family of over 200 funds. All of the funds that are members of The Vanguard Group (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although fund shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds' marketing costs.

Plain Talk About Vanguard's Unique Corporate Structure

The Vanguard Group is owned jointly by the funds it oversees and thus indirectly by the shareholders in those funds. Most other mutual funds are operated by management companies that are owned by third parties—either public or private stockholders—and not by the funds they serve.

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For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended April 30.

The manager primarily responsible for the day-to-day management of the Fund is:

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard's Fixed Income Indexing Americas. He has been with Vanguard since 1998, has worked in investment management since 1999, has managed investment portfolios since 2005, and has managed the Fund since its inception in 2013. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

The Fund's Statement of Additional Information provides information about the portfolio manager's compensation, other accounts under management, and ownership of shares of the Fund.

Dividends, Capital Gains, and Taxes

Fund Distributions

The Fund distributes to shareholders virtually all of its net income (interest less expenses) as well as any net short-term or long-term capital gains realized from the sale of its holdings. Income dividends generally are declared monthly and distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

You can receive distributions of income or capital gains in cash, or you can have them automatically reinvested in more shares of the Fund. However, if you are investing through an employer-sponsored retirement or savings plan, your distributions will be automatically reinvested in additional Fund shares.

Plain Talk About Distributions

As a shareholder, you are entitled to your portion of a fund's income from interest as well as capital gains from the fund's sale of investments. Income consists of interest the fund earns from its money market and bond investments. Capital gains are realized whenever the fund sells securities for higher prices than it paid for them. These capital gains are either short-term or long-term, depending on whether the fund held the securities for one year or less or for more than one year.

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Basic Tax Points

Investors in taxable accounts should be aware of the following basic federal income tax points:

•Distributions are taxable to you whether or not you reinvest these amounts in additional Fund shares.

•Distributions declared in December—if paid to you by the end of January—are taxable as if received in December.

•Any income dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income.

•Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned shares in the Fund.

•Income and capital gains distributions may vary considerably from month to month or year to year, as applicable, as a result of the Fund's normal investment and currency hedging activities and cash flows.

•A sale or exchange of Fund shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

•Any conversion between classes of shares of the same fund is a nontaxable event. By contrast, an exchange between classes of shares of different funds is a taxable event.

•Vanguard (or your intermediary) will send you a statement each year showing the tax status of all of your distributions.

Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on "net investment income." Net investment income takes into account distributions paid by the Fund and capital gains from any sale or exchange of Fund shares.

Income dividends and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes.

The Fund may be subject to foreign taxes or foreign tax withholding on dividends, interest, and some capital gains that it receives on foreign securities. You may qualify for an offsetting credit or deduction under U.S. tax laws for any amount designated as your portion of the Fund's foreign tax obligations, provided that you meet certain requirements. See your tax advisor or IRS publications for more information.

This prospectus provides general tax information only. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

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General Information

Backup withholding. By law, Vanguard must withhold 24% of any taxable distributions or redemptions from your account if you do not:

•Provide your correct taxpayer identification number.

•Certify that the taxpayer identification number is correct.

•Confirm that you are not subject to backup withholding.

Similarly, Vanguard (or your intermediary) must withhold taxes from your account if the IRS instructs us to do so.

Foreign investors. Vanguard funds offered for sale in the United States (Vanguard U.S. funds), including the Fund offered in this prospectus, are not widely available outside the United States. Non-U.S. investors should be aware that U.S. withholding and estate taxes and certain U.S. tax reporting requirements may apply to any investments in Vanguard U.S. funds. Foreign investors should visit the non-U.S. investors page on our website at vanguard.com for information on Vanguard's non-U.S. products.

Invalid addresses. If an income dividend distribution or capital gains distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest the distribution and all future distributions until you provide us with a valid mailing address. Reinvestments will receive the net asset value calculated on the date of the reinvestment.

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not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security).

The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE. The values of any mutual fund shares, including institutional money market fund shares, held by a fund are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a fund are based on the market value of the shares.

A fund also will use fair-value pricing if the value of a security it holds has been materially affected by events occurring before the fund's pricing time but after the close of the principal exchange or market on which the security is traded. This most commonly occurs with foreign securities, which may trade on foreign exchanges or markets that close many hours before the fund's pricing time. Intervening events might be company- specific (e.g., earnings report, material credit events) or country-specific or regional/ global (e.g., natural disaster, economic or political news, act of terrorism, interest rate change). Intervening events include price movements in U.S. markets that exceed a specified threshold or that are otherwise deemed to affect the value of foreign securities. A fund may also use fair-value pricing on bond market holidays when the fund is open for business (such as Columbus Day and Veterans Day).

Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

Vanguard fund share prices are published daily on our website at vanguard.com/prices.

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Financial Highlights

Financial highlights information is intended to help you understand a fund's performance for the past five years (or, if shorter, its period of operations). Certain information reflects financial results for a single fund share. Total return represents the rate that an investor would have earned or lost each period on an investment in a fund or share class (assuming reinvestment of all distributions). This information has been obtained from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report, along with fund financial statements, is included in a fund's most recent annual report to shareholders. You may obtain a free copy of a fund's latest annual or semiannual report, which is available upon request.

1 Calculated based on average shares outstanding.

2 Total returns do not include account service fees that may have applied in the periods shown.

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Total International Bond Index Fund Admiral Shares

1 Calculated based on average shares outstanding.

2 Total returns do not include account service fees that may have applied in the periods shown.

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Investing With Vanguard

This section of the prospectus explains the basics of doing business with Vanguard. Vanguard fund shares can be held directly with Vanguard or indirectly through an intermediary, such as a bank, a broker, or an investment advisor. If you hold Vanguard fund shares directly with Vanguard, you should carefully read each topic within this section that pertains to your relationship with Vanguard. If you hold Vanguard fund shares indirectly through an intermediary (including shares held in a brokerage account through Vanguard Brokerage Services®), please see Investing With Vanguard Through Other Firms, and also refer to your account agreement with the intermediary for information about transacting in that account. If you hold Vanguard fund shares through an employer-sponsored retirement or savings plan, please see Employer-Sponsored Plans. Vanguard reserves the right to change the following policies without notice. Please call or check online for current information. See Contacting Vanguard.

For Vanguard fund shares held directly with Vanguard, each fund you hold in an account is a separate "fund account." For example, if you hold three funds in a nonretirement account titled in your own name, two funds in a nonretirement account titled jointly with your spouse, and one fund in an individual retirement account, you have six fund accounts—and this is true even if you hold the same fund in multiple accounts. Note that each reference to "you" in this prospectus applies to any one or more registered account owners or persons authorized to transact on your account.

Purchasing Shares

Vanguard reserves the right, without notice, to increase or decrease the minimum amount required to open, convert shares to, or maintain a fund account or to add to an existing fund account.

Investment minimums may differ for certain categories of investors.

Account Minimums for Investor Shares

Investor Shares are generally available only to Vanguard funds that operate as funds of funds and to certain retirement plan clients that receive recordkeeping services from Vanguard.

Account Minimums for Admiral Shares

To open and maintain an account. $3,000. Financial intermediaries, institutional clients, and Vanguard-advised clients should contact Vanguard for information on special eligibility rules that may apply to them regarding Admiral Shares. If you are investing through an intermediary, please contact that firm directly for more information regarding your eligibility.

To add to an existing account. Generally $1.

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How to Initiate a Purchase Request

Be sure to check Exchanging Shares, Frequent-Trading Limitations, and Other Rules You Should Know before placing your purchase request.

Online. You may open certain types of accounts, request a purchase of shares, and request an exchange through our website or our mobile application if you are registered for online access.

By telephone. You may call Vanguard to begin the account registration process or request that the account-opening forms be sent to you. You may also call Vanguard to request a purchase of shares in your account or to request an exchange. See Contacting Vanguard.

By mail. You may send Vanguard your account registration form and check to open a new fund account. To add to an existing fund account, you may send your check with an Invest-by-Mail form (from a transaction confirmation or your account statement) or with a deposit slip (available online).

How to Pay for a Purchase

By electronic bank transfer. You may purchase shares of a Vanguard fund through an electronic transfer of money from a bank account. To establish the electronic bank transfer service on an account, you must designate the bank account online, complete a form, or fill out the appropriate section of your account registration form. After the service is set up on your account, you can purchase shares by electronic bank transfer on a regular schedule (Automatic Investment Plan) or upon request. Your purchase request can be initiated online (if you are registered for online access), by telephone, or by mail.

By wire. Wiring instructions vary for different types of purchases. Please call Vanguard for instructions and policies on purchasing shares by wire. See Contacting Vanguard.

By check. You may make initial or additional purchases to your fund account by sending a check with a deposit slip or by utilizing our mobile application if you are registered for online access. Also see How to Initiate a Purchase Request. Make your check payable to Vanguard and include the appropriate fund number (e.g., Vanguard—xx). For a list of Fund numbers (for share classes in this prospectus), see Additional Information.

By exchange. You may purchase shares of a Vanguard fund using the proceeds from the simultaneous redemption of shares of another Vanguard fund. You may initiate an exchange online (if you are registered for online access), by telephone, or by mail with an exchange form. See Exchanging Shares.

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Trade Date

The trade date for any purchase request received in good order will depend on the day and time Vanguard receives your request, the manner in which you are paying, and the type of fund you are purchasing. Your purchase will be executed using the NAV as calculated on the trade date. See Share Price.

For purchases by check into all funds other than money market funds and for purchases by exchange, wire, or electronic bank transfer into all funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date for the purchase will be the same day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date for the purchase will be the next business day.

For purchases by check into money market funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date for the purchase will be the next business day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date for the purchase will be the second business day following the day Vanguard receives the purchase request. Because money market instruments must be purchased with federal funds and it takes a money market mutual fund one business day to convert check proceeds into federal funds, the trade date for the purchase will be one business day later than for other funds.

If your purchase request is not accurate and complete, it may be rejected. See Other Rules You Should Know—Good Order.

For further information about purchase transactions, consult our website at vanguard.com or see Contacting Vanguard.

Other Purchase Rules You Should Know

Admiral Shares. Admiral Shares generally are not available for SIMPLE IRAs and Vanguard Individual 401(k) Plans.

Check purchases. All purchase checks must be written in U.S. dollars, be drawn on a U.S. bank, and be accompanied by good order instructions. Vanguard does not accept cash, traveler's checks, starter checks, or money orders. In addition, Vanguard may refuse checks that are not made payable to Vanguard.

New accounts. We are required by law to obtain from you certain personal information that we will use to verify your identity. If you do not provide the information, we may not be able to open your account. If we are unable to verify your identity, Vanguard reserves the right, without notice, to close your account or take such other steps as we deem reasonable. Certain types of accounts may require additional documentation.

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Refused or rejected purchase requests. Vanguard reserves the right to stop selling fund shares or to reject any purchase request at any time and without notice, including, but not limited to, purchases requested by exchange from another Vanguard fund. This also includes the right to reject any purchase request because the investor has a history of frequent trading or because the purchase may negatively affect a fund's operation or performance.

Large purchases. Call Vanguard before attempting to invest a large dollar amount.

No cancellations. Vanguard will not accept your request to cancel any purchase request once processing has begun. Please be careful when placing a purchase request.

Converting Shares

When a conversion occurs, you receive shares of one class in place of shares of another class of the same fund. At the time of conversion, the dollar value of the "new" shares you receive equals the dollar value of the "old" shares that were converted. In other words, the conversion has no effect on the value of your investment in the fund at the time of the conversion. However, the number of shares you own after the conversion may be greater than or less than the number of shares you owned before the conversion, depending on the NAVs of the two share classes.

Vanguard will not accept your request to cancel any self-directed conversion request once processing has begun. Please be careful when placing a conversion request.

A conversion between share classes of the same fund is a nontaxable event.

Trade Date

The trade date for any conversion request received in good order will depend on the day and time Vanguard receives your request. Your conversion will be executed using the NAVs of the different share classes on the trade date. See Share Price.

For a conversion request (other than a request to convert to ETF Shares) received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. For a conversion request received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day. See Other Rules You Should Know.

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Conversions to Institutional Shares

You are eligible for a self-directed conversion from another share class to Institutional Shares of the Fund, provided that your account meets all Institutional Shares' eligibility requirements. You may request a conversion through our website (if you are registered for online access), or you may contact Vanguard by telephone or by mail to request this transaction. Accounts that qualify for Institutional Shares will not be automatically converted.

Conversions to Institutional Select Shares

You are eligible for a self-directed conversion from another share class to Institutional Select Shares of the Fund, provided that your account meets all eligibility requirements. You may request a conversion through our website (if you are registered for online access), through a trading platform, by mail, or by telephone. Accounts that qualify for Institutional Select Shares will not be automatically converted.

Conversions to ETF Shares

Owners of conventional shares (i.e., not exchange-traded shares) issued by the Fund may convert those shares to ETF Shares of equivalent value of the same fund. Please note that investors who own conventional shares through a 401(k) plan or other employer-sponsored retirement or benefit plan generally may not convert those shares to ETF Shares and should check with their plan sponsor or recordkeeper. ETF Shares, whether acquired through a conversion or purchased on the secondary market, cannot be converted to conventional shares by a shareholder. Also, ETF Shares of one fund cannot be exchanged for ETF Shares of another fund.

ETF Shares must be held in a brokerage account. Thus, before converting conventional shares to ETF Shares, you must have an existing, or open a new, brokerage account. This account may be with Vanguard Brokerage Services or with any other brokerage firm.

Vanguard Brokerage Services does not impose a fee on conversions from conventional shares to Vanguard ETF Shares. However, other brokerage firms may charge a fee to process a conversion. Vanguard reserves the right, in the future, to impose a transaction fee on conversions or to limit, temporarily suspend, or terminate the conversion privilege. For additional information on converting conventional shares to ETF Shares, please contact Vanguard to obtain a prospectus for ETF Shares. See Contacting Vanguard.

Mandatory Conversions to Another Share Class

If an account no longer meets the balance requirements for a share class, Vanguard may automatically convert the shares in the account to another share class, as

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appropriate. A decline in the account balance because of market movement may result in such a conversion. Vanguard will notify the investor in writing before any mandatory conversion occurs.

Redeeming Shares

How to Initiate a Redemption Request

Be sure to check Exchanging Shares, Frequent-Trading Limitations, and Other Rules You Should Know before placing your redemption request.

Online. You may request a redemption of shares or request an exchange through our website or our mobile application if you are registered for online access.

By telephone. You may call Vanguard to request a redemption of shares or an exchange. See Contacting Vanguard.

By mail. You may send a form (available online) to Vanguard to redeem from a fund account or to make an exchange.

How to Receive Redemption Proceeds

By electronic bank transfer. You may have the proceeds of a fund redemption sent directly to a designated bank account. To establish the electronic bank transfer service on an account, you must designate a bank account online, complete a form, or fill out the appropriate section of your account registration form. After the service is set up on your account, you can redeem shares by electronic bank transfer on a regular schedule (Automatic Withdrawal Plan) or upon request. Your redemption request can be initiated online (if you are registered for online access), by telephone, or by mail.

By wire. To receive your proceeds by wire, you may instruct Vanguard to wire your redemption proceeds ($100 minimum) to a previously designated bank account. To establish the wire redemption service, you generally must designate a bank account online, complete a form, or fill out the appropriate section of your account registration form.

Please note that Vanguard charges a $10 wire fee for outgoing wire redemptions. The fee is assessed in addition to, rather than being withheld from, redemption proceeds and is paid directly to the fund in which you invest. For example, if you redeem $100 via a wire, you will receive the full $100, and the $10 fee will be assessed to your fund account through an additional redemption of fund shares. If you redeem your entire fund account, your redemption proceeds will be reduced by the amount of the fee. The wire fee does not apply to accounts held by Flagship and Flagship Select clients; accounts held through intermediaries, including Vanguard Brokerage Services; or accounts held by institutional clients.

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By exchange. You may have the proceeds of a Vanguard fund redemption invested directly in shares of another Vanguard fund. You may initiate an exchange online (if you are registered for online access), by telephone, or by mail. See Exchanging Shares.

By check. If you have not chosen another redemption method, Vanguard will mail you a redemption check, generally payable to all registered account owners, normally within two business days of your trade date, and generally to the address of record.

Trade Date

The trade date for any redemption request received in good order will depend on the day and time Vanguard receives your request and the manner in which you are redeeming. Your redemption will be executed using the NAV as calculated on the trade date. See Share Price.

For redemptions by check, exchange, or wire: If the redemption request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the redemption request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

•Note on timing of wire redemptions from money market funds: For telephone requests received by Vanguard on a business day before 10:45 a.m., Eastern time (2 p.m., Eastern time, for Vanguard Prime Money Market Fund; 12:30 p.m., Eastern time, for Vanguard Federal Money Market Fund), the redemption proceeds generally will leave Vanguard by the close of business the same day. For telephone requests received by Vanguard on a business day after those cut-off times, or on a nonbusiness day, and for all requests other than by telephone, the redemption proceeds generally will leave Vanguard by the close of business on the next business day.

•Note on timing of wire redemptions from all other funds: For requests received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the redemption proceeds generally will leave Vanguard by the close of business on the next business day. For requests received by Vanguard on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the redemption proceeds generally will leave Vanguard by the close of business on the second business day after Vanguard receives the request.

For redemptions by electronic bank transfer: If the redemption request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the redemption request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

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If your redemption request is not accurate and complete, it may be rejected. If we are unable to send your redemption proceeds by wire or electronic bank transfer because the receiving institution rejects the transfer, Vanguard will make additional efforts to complete your transaction. If Vanguard is still unable to complete the transaction, we may send the proceeds of the redemption to you by check, generally payable to all registered account owners, or use your proceeds to purchase new shares of the fund from which you sold shares for the purpose of the wire or electronic bank transfer transaction. See Other Rules You Should Know—Good Order.

If your redemption request is received in good order, we typically expect that redemption proceeds will be paid by the Fund within one business day of the trade date; however, in certain circumstances, investors may experience a longer settlement period at the time of the transaction. For further information, see "Potentially disruptive redemptions" and "Emergency circumstances."

For further information about redemption transactions, consult our website at vanguard.com or see Contacting Vanguard.

Other Redemption Rules You Should Know

Documentation for certain accounts. Special documentation may be required to redeem from certain types of accounts, such as trust, corporate, nonprofit, or retirement accounts. Please call us before attempting to redeem from these types of accounts.

Potentially disruptive redemptions. Vanguard reserves the right to pay all or part of a redemption in kind—that is, in the form of securities—if we reasonably believe that a cash redemption would negatively affect the fund's operation or performance or that the shareholder may be engaged in market-timing or frequent trading. Under these circumstances, Vanguard also reserves the right to delay payment of the redemption proceeds for up to seven calendar days. By calling us before you attempt to redeem a large dollar amount, you may avoid in-kind or delayed payment of your redemption. Please see Frequent-Trading Limitations for information about Vanguard's policies to limit frequent trading.

Recently purchased shares. Although you can redeem shares at any time, proceeds may not be made available to you until the fund collects payment for your purchase. This may take up to seven calendar days for shares purchased by check or by electronic bank transfer. If you have written a check on a fund with checkwriting privileges, that check may be rejected if your fund account does not have a sufficient available balance.

Address change. If you change your address online or by telephone, there may be up to a 14-day restriction on your ability to request check redemptions online and by telephone. You can request a redemption in writing (using a form available online) at

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any time. Confirmations of address changes are sent to both the old and new addresses.

Payment to a different person or address. At your request, we can make your redemption check payable, or wire your redemption proceeds, to a different person or send it to a different address. However, this generally requires the written consent of all registered account owners and may require additional documentation, such as a signature guarantee or a notarized signature. You may obtain a signature guarantee from some commercial or savings banks, credit unions, trust companies, or member firms of a U.S. stock exchange.

No cancellations. Vanguard will not accept your request to cancel any redemption request once processing has begun. Please be careful when placing a redemption request.

Emergency circumstances. Vanguard funds can postpone payment of redemption proceeds for up to seven calendar days. In addition, Vanguard funds can suspend redemptions and/or postpone payments of redemption proceeds beyond seven calendar days at times when the NYSE is closed or during emergency circumstances, as determined by the SEC.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of one Vanguard fund to simultaneously purchase shares of a different Vanguard fund. You can make exchange requests online (if you are registered for online access), by telephone, or by mail. See Purchasing Shares and Redeeming Shares.

If the NYSE is open for regular trading (generally until 4 p.m., Eastern time, on a business day) at the time an exchange request is received in good order, the trade date generally will be the same day. See Other Rules You Should Know—Good Order for additional information on all transaction requests.

Vanguard will not accept your request to cancel any exchange request once processing has begun. Please be careful when placing an exchange request.

Call Vanguard before attempting to exchange a large dollar amount. By calling us before you attempt to exchange a large dollar amount, you may avoid delayed or rejected transactions.

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Please note that Vanguard reserves the right, without notice, to revise or terminate the exchange privilege, limit the amount of any exchange, or reject an exchange, at any time, for any reason. See Frequent-Trading Limitations for additional restrictions on exchanges.

Frequent-Trading Limitations

Because excessive transactions can disrupt management of a fund and increase the fund's costs for all shareholders, the board of trustees of each Vanguard fund places certain limits on frequent trading in the funds. Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation- Protected Securities Index Fund) limits an investor's purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account. ETF Shares are not subject to these frequent-trading limits.

For Vanguard Retirement Investment Program pooled plans, the limitations apply to exchanges made online or by telephone.

These frequent-trading limitations do not apply to the following:

•Purchases of shares with reinvested dividend or capital gains distributions.

•Transactions through Vanguard's Automatic Investment Plan, Automatic Exchange Service, Direct Deposit Service, Automatic Withdrawal Plan, Required Minimum Distribution Service, and Vanguard Small Business Online®.

•Discretionary transactions through Vanguard Personal Advisor Services®, Vanguard Institutional Advisory Services®, and Vanguard Digital AdvisorTM.

•Redemptions of shares to pay fund or account fees.

•Redemptions of shares to remove excess shareholder contributions to certain types of retirement accounts (including, but not limited to, IRAs and Vanguard Individual 401(k) Plans).

•Transfers and reregistrations of shares within the same fund.

•Purchases of shares by asset transfer or direct rollover.

•Conversions of shares from one share class to another in the same fund.

•Checkwriting redemptions.

•Section 529 college savings plans.

•Certain approved institutional portfolios and asset allocation programs, as well as trades made by funds or trusts managed by Vanguard or its affiliates that invest in other Vanguard funds. (Please note that shareholders of Vanguard's funds of funds are subject to the limitations.)

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For participants in employer-sponsored defined contribution plans,* the frequent- trading limitations do not apply to:

•Purchases of shares with participant payroll or employer contributions or loan repayments.

•Purchases of shares with reinvested dividend or capital gains distributions.

•Distributions, loans, and in-service withdrawals from a plan.

•Redemptions of shares as part of a plan termination or at the direction of the plan.

•Transactions executed through the Vanguard Managed Account Program.

•Redemptions of shares to pay fund or account fees.

•Share or asset transfers or rollovers.

•Reregistrations of shares.

•Conversions of shares from one share class to another in the same fund.

•Exchange requests submitted by written request to Vanguard. (Exchange requests submitted by fax, if otherwise permitted, are subject to the limitations.)

*The following Vanguard fund accounts are subject to the frequent-trading limitations: SEP-IRAs, SIMPLE IRAs, certain Individual 403(b)(7) Custodial Accounts, and Vanguard Individual 401(k) Plans.

Accounts Held by Institutions (Other Than Defined Contribution Plans)

Vanguard will systematically monitor for frequent trading in institutional clients' accounts. If we detect suspicious trading activity, we will investigate and take appropriate action, which may include applying to a client's accounts the 30-day policy previously described, prohibiting a client's purchases of fund shares, and/or revoking the client's exchange privilege.

Accounts Held by Intermediaries

When intermediaries establish accounts in Vanguard funds for the benefit of their clients, we cannot always monitor the trading activity of the individual clients. However, we review trading activity at the intermediary (omnibus) level, and if we detect suspicious activity, we will investigate and take appropriate action. If necessary, Vanguard may prohibit additional purchases of fund shares by an intermediary, including for the benefit of certain of the intermediary's clients. Intermediaries also may monitor their clients' trading activities with respect to Vanguard funds.

For those Vanguard funds that charge purchase and/or redemption fees, intermediaries will be asked to assess these fees on client accounts and remit these fees to the funds. The application of purchase and redemption fees and frequent- trading limitations may vary among intermediaries. There are no assurances that

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Vanguard will successfully identify all intermediaries or that intermediaries will properly assess purchase and redemption fees or administer frequent-trading limitations. If you invest with Vanguard through an intermediary, please read that firm's materials carefully to learn of any other rules or fees that may apply.

Other Rules You Should Know

Prospectus and Shareholder Report Mailings

When two or more shareholders have the same last name and address, just one summary prospectus (or prospectus) and/or shareholder report may be sent in an attempt to eliminate the unnecessary expense of duplicate mailings. You may request individual prospectuses and reports by contacting our Client Services Department by telephone or online. See Contacting Vanguard.

Vanguard.com

Registration. If you are a registered user of vanguard.com, you can review your account holdings; buy, sell, or exchange shares of most Vanguard funds; and perform most other transactions through our website. You must register for this service online.

Electronic delivery. Vanguard can deliver your account statements, transaction confirmations, prospectuses, certain tax forms, and shareholder reports electronically. If you are a registered user of vanguard.com, you can consent to the electronic delivery of these documents by logging on and changing your mailing preferences under "Account Maintenance." You can revoke your electronic consent at any time through our website, and we will begin to send paper copies of these documents within 30 days of receiving your revocation.

Telephone Transactions

Automatic. When we set up your account, we will automatically enable you to do business with us by telephone, unless you instruct us otherwise in writing.

Tele-Account®. To obtain fund and account information through Vanguard's automated telephone service, you must first establish a Personal Identification Number (PIN) by calling Tele-Account at 800-662-6273.

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Proof of a caller's authority. We reserve the right to refuse a telephone request if the caller is unable to provide the requested information or if we reasonably believe that the caller is not an individual authorized to act on the account. Before we allow a caller to act on an account, we may request the following information:

•Authorization to act on the account (as the account owner or by legal documentation or other means).

•Account registration and address.

•Fund name and account number, if applicable.

•Other information relating to the caller, the account owner, or the account.

Good Order

We reserve the right to reject any transaction instructions that are not in "good order." Good order generally means that your instructions:

•Are provided by the person(s) authorized in accordance with Vanguard's policies and procedures to access the account and request transactions.

•Include the fund name and account number.

•Include the amount of the transaction (stated in dollars, shares, or percentage). Written instructions also must generally be provided on a Vanguard form and include:

•Signature(s) and date from the authorized person(s).

•Signature guarantees or notarized signatures, if required for the type of transaction. (Call Vanguard for specific requirements.)

•Any supporting documentation that may be required.

Good order requirements may vary among types of accounts and transactions. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Vanguard reserves the right, without notice, to revise the requirements for good order.

Future Trade-Date Requests

Vanguard does not accept requests to hold a purchase, conversion, redemption, or exchange transaction for a future date. All such requests will receive trade dates as previously described in Purchasing Shares, Converting Shares, Redeeming Shares, and Exchanging Shares. Vanguard reserves the right to return future-dated purchase checks.

Accounts With More Than One Owner

If an account has more than one owner or authorized person, Vanguard generally will accept instructions from any one owner or authorized person.

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Responsibility for Fraud

You should take precautions to protect yourself from fraud. Keep your account-related information private, and review any account confirmations, statements, or other information that we provide to you as soon as you receive them. Let us know immediately if you discover unauthorized activity or see something on your account that you do not understand or that looks unusual.

Vanguard will not be responsible for losses that result from transactions by a person who we reasonably believe is authorized to act on your account.

Uncashed Checks

Please cash your distribution or redemption checks promptly. Vanguard will not pay interest on uncashed checks. Vanguard may be required to transfer assets related to uncashed checks to a state under the state's abandoned property law.

Dormant Accounts

If your account has no activity in it for a period of time, Vanguard may be required to transfer it to a state under the state's abandoned property law, subject to potential federal or state withholding taxes.

Unusual Circumstances

If you experience difficulty contacting Vanguard online or by telephone, you can send us your transaction request on a Vanguard form by regular or express mail.

Investing With Vanguard Through Other Firms

You may purchase or sell shares of most Vanguard funds through a financial intermediary, such as a bank, a broker, or an investment advisor. Please consult your financial intermediary to determine which, if any, shares are available through that firm and to learn about other rules that may apply. Your financial intermediary can provide you with account information and any required tax forms. You may be required to pay a commission on purchases of mutual fund shares made through a financial intermediary.

Please see Frequent-Trading Limitations—Accounts Held by Intermediaries for information about the assessment of any purchase or redemption fees and the monitoring of frequent trading for accounts held by intermediaries.

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Account Service Fee

Vanguard may charge a $20 account service fee on fund accounts that have a balance below $10,000 for any reason, including market fluctuation. The account service fee applies to both retirement and nonretirement fund accounts and may be assessed on fund accounts in all Vanguard funds, regardless of the account minimum. The fee, which will be collected by redeeming fund shares in the amount of $20, will be deducted from fund accounts subject to the fee once per calendar year.

If you elect to receive your statements and other materials electronically (i.e., by e-delivery), the account service fee will not be charged, so long as your election remains in effect. You can make your e-delivery election on vanguard.com.

Beginning on January 1, 2021, you may elect to receive paper copies of shareholder reports free of charge as noted on the cover of this prospectus.

Certain account types have alternative fee structures, including SIMPLE IRAs, Vanguard Retirement Investment Program pooled plans, and Vanguard Individual 401(k) Plans.

Low-Balance Accounts

The Fund reserves the right to liquidate a fund account whose balance falls below the account minimum for any reason, including market fluctuation. This liquidation policy applies to nonretirement fund accounts and accounts that are held through intermediaries. Any such liquidation will be preceded by written notice to the investor.

Right to Change Policies

In addition to the rights expressly stated elsewhere in this prospectus, Vanguard reserves the right, without notice, to (1) alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, conversion, service, or privilege at any time and (2) alter, impose, discontinue, or waive any purchase fee, redemption fee, account service fee, or other fee charged to a shareholder or a group of shareholders. Changes may affect any or all investors. These actions will be taken when, at the sole discretion of Vanguard management, Vanguard believes they are in the best interest of a fund.

Account Restrictions

Vanguard reserves the right to: (1) redeem all or a portion of a fund/account to meet a legal obligation, including tax withholding, tax lien, garnishment order, or other obligation imposed on your account by a court or government agency; (2) redeem shares, close an account, or suspend account privileges, features, or options in the case of threatening conduct or activity; (3) redeem shares, close an account, or suspend account privileges, features, or options if Vanguard believes or suspects that not doing so could result in a suspicious, fraudulent, or illegal transaction; (4) place restrictions on the ability to redeem any or all shares in an account if it is required to

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do so by a court or government agency; (5) place restrictions on the ability to redeem any or all shares in an account if Vanguard believes that doing so will prevent fraud, financial exploitation or abuse, or to protect vulnerable investors; (6) freeze any account and/or suspend account services if Vanguard has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners; and (7) freeze any account and/or suspend account services upon initial notification to Vanguard of the death of an account owner.

Share Classes

Vanguard reserves the right, without notice, to change the eligibility requirements of its share classes, including the types of clients who are eligible to purchase each share class.

Fund and Account Updates

Confirmation Statements

We will send (or provide through our website, whichever you prefer) a confirmation of your trade date and the amount of your transaction when you buy, sell, exchange, or convert shares. However, we will not send confirmations reflecting only checkwriting redemptions or the reinvestment of dividend or capital gains distributions. For any month in which you had a checkwriting redemption, a Checkwriting Activity Statement will be sent to you itemizing the checkwriting redemptions for that month. Promptly review each confirmation statement that we provide to you. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on a confirmation statement, or Vanguard will consider the transaction properly processed.

Portfolio Summaries

We will send (or provide through our website, whichever you prefer) quarterly portfolio summaries to help you keep track of your accounts throughout the year. Each summary shows the market value of your account at the close of the statement period, as well as all distributions, purchases, redemptions, exchanges, transfers, and conversions for the current calendar quarter (or month). Promptly review each summary that we provide to you. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on the summary, or Vanguard will consider the transaction properly processed.

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Tax Information Statements

For most accounts, Vanguard (or your intermediary) is required to provide annual tax forms to assist you in preparing your income tax returns. These forms are generally available for each calendar year early in the following year. Registered users of vanguard.com can also view certain forms through our website. Vanguard (or your intermediary) may also provide you with additional tax-related documentation. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Annual and Semiannual Reports

We will send (or provide through our website, whichever you prefer) reports about Vanguard Total International Bond Index Fund twice a year, in June and December. These reports include overviews of the financial markets and provide the following specific Fund information:

•Performance assessments and comparisons with industry benchmarks.

•Financial statements with listings of Fund holdings.

Portfolio Holdings

Please consult the Fund's Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund's portfolio holdings.

Employer-Sponsored Plans

Your plan administrator or your employee benefits office can provide you with detailed information on how to participate in your plan and how to elect the Fund as an investment option.

•If you have any questions about the Fund or Vanguard, including those about the Fund's investment objective, strategies, or risks, contact Vanguard Participant Services toll-free at 800-523-1188 or visit our website at vanguard.com.

•If you have questions about your account, contact your plan administrator or the organization that provides recordkeeping services for your plan.

•Be sure to carefully read each topic that pertains to your transactions with Vanguard.

Vanguard reserves the right to change its policies without notice to shareholders.

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Transactions

Processing times for your transaction requests may differ among recordkeepers or among transaction and funding types. Your plan's recordkeeper (which may also be Vanguard) will determine the necessary processing time frames for your transaction requests prior to submission to the Fund. Consult your recordkeeper or plan administrator for more information.

If Vanguard is serving as your plan recordkeeper and if your transaction involves one or more investments with an early cut-off time for processing or another trading restriction, your entire transaction will be subject to the restriction when the trade date for your transaction is determined.

Contacting Vanguard

Web

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CFA® is a registered trademark owned by CFA Institute.

BLOOMBERG is a trademark and service mark of Bloomberg Finance L.P. BARCLAYS is a trademark and service mark of Barclays Bank Plc, used under license. Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL) (collectively, Bloomberg), or Bloomberg's licensors, own all proprietary rights in the Bloomberg Barclays Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged) (the Index or Bloomberg Barclays Index).

Neither Barclays Bank Plc, Barclays Capital Inc., or any affiliate (collectively Barclays) or Bloomberg is the issuer or producer of the Total International Bond Index Fund and neither Bloomberg nor Barclays has any responsibilities, obligations or duties to investors in the Total International Bond Index Fund. The Index is licensed for use by The Vanguard Group, Inc. (Vanguard) as the sponsor of the Total International Bond Index Fund. Bloomberg and Barclays' only relationship with Vanguard in respect to the Index is the licensing of the Index, which is determined, composed and calculated by BISL, or any successor thereto, without regard to the Issuer or the Total International Bond Index Fund or the owners of the Total International Bond Index Fund.

Additionally, Vanguard may for itself execute transaction(s) with Barclays in or relating to the Index in connection with the Total International Bond Index Fund. Investors acquire the Total International Bond Index Fund from Vanguard and investors neither acquire any interest in the Index nor enter into any relationship of any kind whatsoever with Bloomberg or Barclays upon making an investment in the Total International Bond Index Fund. The Total International Bond Index Fund is not sponsored, endorsed, sold or promoted by Bloomberg or Barclays. Neither Bloomberg nor Barclays makes any representation or warranty, express or implied regarding the advisability of investing in the Total International Bond Index Fund or the advisability of investing in securities generally or the ability of the Index to track corresponding or relative market performance. Neither Bloomberg nor Barclays has passed on the legality or suitability of the Total International Bond Index Fund with respect to any person or entity. Neither Bloomberg nor Barclays is responsible for and has not participated in the determination of the timing of, prices at, or quantities of the Total International Bond Index Fund to be issued. Neither Bloomberg nor Barclays has any obligation to take the needs of the Issuer or the owners of the Total International Bond Index Fund or any other third party into consideration in determining, composing or calculating the Index. Neither Bloomberg nor Barclays has any obligation or liability in connection with administration, marketing or trading of the Total International Bond Index Fund.

The licensing agreement between Bloomberg and Barclays is solely for the benefit of Bloomberg and Barclays and not for the benefit of the owners of the Total International Bond Index Fund, investors or other third parties. In addition, the licensing agreement between Vanguard and Bloomberg is solely for the benefit of Vanguard and Bloomberg and not for the benefit of the owners of the Total International Bond Index Fund, investors or other third parties.

NEITHER BLOOMBERG NOR BARCLAYS SHALL HAVE ANY LIABILITY TO THE ISSUER, INVESTORS OR TO OTHER THIRD PARTIES FOR THE QUALITY, ACCURACY AND/OR COMPLETENESS OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR FOR INTERRUPTIONS IN THE DELIVERY OF THE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE ISSUER, THE INVESTORS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY EXPRESS OR IMPLIED WARRANTIES, AND EACH HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. BLOOMBERG RESERVES THE RIGHT TO CHANGE THE METHODS OF CALCULATION OR PUBLICATION, OR TO CEASE THE CALCULATION OR PUBLICATION OF THE BLOOMBERG BARCLAYS INDEX, AND NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY MISCALCULATION OF OR ANY INCORRECT, DELAYED OR INTERRUPTED PUBLICATION WITH RESPECT TO THE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY DAMAGES, INCLUDING, WITHOUT LIMITATION, ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY LOST PROFITS AND EVEN IF ADVISED OF THE POSSIBILITY OF SUCH, RESULTING FROM THE USE OF A BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR WITH RESPECT TO THE TOTAL INTERNATIONAL BOND INDEX FUND.

None of the information supplied by Bloomberg or Barclays and used in this publication may be reproduced in any manner without the prior written permission of both Bloomberg and Barclays Capital, the investment banking division of Barclays Bank Plc. Barclays Bank Plc is registered in England No. 1026167. Registered office 1 Churchill Place London E14 5HP.

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Glossary of Investment Terms

Average Maturity. The average length of time until bonds held by a fund reach maturity and are repaid. In general, the longer the average maturity, the more a fund's share price fluctuates in response to changes in market interest rates. In calculating average maturity, a fund uses a bond's maturity or, if applicable, an earlier date on which the advisor believes it is likely that a maturity-shortening device (such as a call, a put, a refunding, a prepayment, or a redemption provision or an adjustable coupon rate) will cause the bond to be repaid.

Bond. A debt security (IOU) issued by a corporation, a government, or a government agency in exchange for the money the bondholder lends it. In most instances, the issuer agrees to pay back the loan by a specific date and generally to make regular interest payments until that date.

Capital Gains Distributions. Payments to mutual fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Coupon Rate. The interest rate paid by the issuer of a debt security until its maturity. It is expressed as an annual percentage of the face value of the security.

Dividend Distributions. Payments to mutual fund shareholders of income from interest or dividends generated by a fund's investments.

Expense Ratio. A fund's total annual operating expenses expressed as a percentage of the fund's average net assets. The expense ratio includes management and administrative expenses, but it does not include the transaction costs of buying and selling portfolio securities.

Face Value. The amount to be paid at a bond's maturity; also known as the par value or principal.

Fixed Income Security. An investment, such as a bond, representing a debt that must be repaid by a specified date, and on which the borrower must pay a fixed, variable, or floating rate of interest.

Float-Adjusted Index. An index that weights its constituent securities based on the value of the constituent securities that are available for public trading, rather than the value of all constituent securities. Some portion of an issuer's securities may be unavailable for public trading because, for example, those securities are owned by company insiders on a restricted basis or by a government agency. By excluding unavailable securities, float-adjusted indexes can produce a more accurate picture of the returns actually experienced by investors in the measured market.

Inception Date. The date on which the assets of a fund (or one of its share classes) are first invested in accordance with the fund's investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.

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P.O. Box 2600

Valley Forge, PA 19482-2600

Connect with Vanguard® > vanguard.com

P 1231 022020

ETF Summary

1

Example

The following example is intended to help you compare the cost of investing in the Fund's ETF Shares with the cost of investing in other funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to sell your shares at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

This example does not include the brokerage commissions that you may pay to buy and sell ETF Shares of the Fund.

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 26% of the average value of its portfolio.

2

constitute 5% or more of the Index, then the excess would be reallocated to bonds of other issuers represented in the Index. The Index methodology is not designed to satisfy the diversification requirements of the Investment Company Act of 1940. The Fund will attempt to hedge its foreign currency exposure, primarily through the use of foreign currency exchange forward contracts, in order to correlate to the returns of the Index, which is U.S. dollar hedged. Such hedging is intended to minimize the currency risk associated with investment in bonds denominated in currencies other than the U.S. dollar.

The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund's investments will be selected through the sampling process and, under normal circumstances, at least 80% of the Fund's assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of October 31, 2019, the dollar-weighted average maturity of the Index was 9.9 years.

3

•Credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. Credit risk should be relatively low for the Fund because it purchases only bonds that are of investment-grade quality.

•Call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond's call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. Such redemptions and subsequent reinvestments would also increase the Fund's portfolio turnover rate. Call risk should be low for the Fund because it invests only a small portion of its assets in callable bonds.

•Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

•Currency risk and currency hedging risk. The Fund seeks to mimic the performance of foreign bonds without regard to currency exchange rate fluctuations. To accomplish this goal, the Fund attempts to offset, or hedge, its foreign currency exposure by entering into currency hedging transactions, primarily through the use of foreign currency exchange forward contracts (a type of derivative). However, it generally is not possible to perfectly hedge the Fund's foreign currency exposure. The Fund will decline in value if it underhedges a currency that has weakened or overhedges a currency that has strengthened relative to the U.S. dollar. In addition, the Fund will incur expenses to hedge its foreign currency exposure. By entering into currency hedging transactions, the Fund may eliminate any chance to benefit from favorable fluctuations in relevant currency exchange rates. Currency risk and currency hedging risk for the Fund is low. The Fund's use of foreign currency exchange forward contracts also subjects the Fund to counterparty risk, which is the chance that the counterparty to a currency forward contract with the Fund will be unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

•Derivatives risk. The Fund may invest in derivatives, which may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

Because ETF Shares are traded on an exchange, they are subject to additional risks:

•The Fund's ETF Shares are listed for trading on Nasdaq and are bought and sold on the secondary market at market prices. Although it is expected that the market price of an ETF Share typically will approximate its net asset value (NAV), there may be times when the market price and the NAV differ significantly. Thus, you may pay more or less than NAV when you buy ETF Shares on the secondary market, and you may receive more or less than NAV when you sell those shares.

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•Although the Fund's ETF Shares are listed for trading on Nasdaq, it is possible that an active trading market may not be maintained.

•Trading of the Fund's ETF Shares may be halted by the activation of individual or marketwide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). Trading of the Fund's ETF Shares may also be halted if (1) the shares are delisted from Nasdaq without first being listed on another exchange or (2) Nasdaq officials determine that such action is appropriate in the interest of a fair and orderly market or for the protection of investors.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund's ETF Shares (based on NAV) has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the ETF Shares compare with those of the Fund's target index, which has investment characteristics similar to those of the Fund. Keep in mind that the Fund's past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

-40%

During the periods shown in the bar chart, the highest return for a calendar quarter was 3.46% (quarter ended March 31, 2016), and the lowest return for a quarter was –2.92% (quarter ended June 30, 2015).

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Average Annual Total Returns for Periods Ended December 31, 2019

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

6

Purchase and Sale of Fund Shares

You can buy and sell ETF Shares of the Fund through a brokerage firm. The price you pay or receive for ETF Shares will be the prevailing market price, which may be more or less than the NAV of the shares. The brokerage firm may charge you a commission to execute the transaction. Unless imposed by your brokerage firm, there is no minimum dollar amount you must invest and no minimum number of shares you must buy. ETF Shares of the Fund cannot be directly purchased from or redeemed with the Fund, except by certain authorized broker-dealers. These broker-dealers may purchase and redeem ETF Shares only in large blocks (Creation Units), typically in exchange for cash.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gain. If you are investing through a tax-advantaged account, such as an IRA or an employer- sponsored retirement or savings plan, special tax rules apply.

Payments to Financial Intermediaries

The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.

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Investing in Vanguard ETF® Shares

What Are Vanguard ETF Shares?

Vanguard ETF Shares are an exchange-traded class of shares issued by certain Vanguard funds. ETF Shares represent an interest in the portfolio of stocks or bonds held by the issuing fund. This prospectus describes Vanguard Total International Bond ETF, a class of shares issued by Vanguard Total International Bond Index Fund. In addition to ETF Shares, the Fund offers four conventional (not exchange-traded) classes of shares. This prospectus, however, relates only to ETF Shares.

How Are Vanguard ETF Shares Different From Conventional Mutual Fund Shares?

Conventional mutual fund shares can be directly purchased from and redeemed with the issuing fund for cash at the net asset value (NAV), typically calculated once a day. ETF Shares, by contrast, cannot be purchased directly from or redeemed directly with the issuing fund by an individual investor. Rather, ETF Shares can only be purchased or redeemed directly from the issuing fund by certain authorized broker-dealers. These broker-dealers may purchase and redeem ETF Shares only in large blocks (Creation Units), usually in exchange for baskets of securities and not for cash (although some funds issue and redeem Creation Units in exchange for cash or a combination of cash and securities).

An organized secondary trading market is expected to exist for ETF Shares, unlike conventional mutual fund shares, because ETF Shares are listed for trading on a national securities exchange. Individual investors can purchase and sell ETF Shares on the secondary market through a broker. Secondary-market transactions occur not at NAV, but at market prices that are subject to change throughout the day based on the supply of and demand for ETF Shares, changes in the prices of the fund's portfolio holdings, and other factors.

The market price of a fund's ETF Shares typically will differ somewhat from the NAV of those shares. The difference between market price and NAV is expected to be small most of the time, but in times of market disruption or extreme market volatility, the difference may become significant.

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How Do I Buy and Sell Vanguard ETF Shares?

ETF Shares of the Fund are listed for trading on Nasdaq. You can buy and sell ETF Shares on the secondary market in the same way you buy and sell any other exchange-traded security—through a broker. Your broker may charge a commission to execute a transaction. You will also incur the cost of the "bid-ask spread," which is the difference between the price a dealer will pay for a security and the somewhat higher price at which the dealer will sell the same security. Because secondary-market transactions occur at market prices, you may pay more (premium) or less (discount) than NAV when you buy ETF Shares and receive more or less than NAV when you sell those shares. In times of severe market disruption, the bid-ask spread and premiums/ discounts can increase significantly. Unless imposed by your broker, there is no minimum dollar amount you must invest and no minimum number of ETF Shares you must buy.

Your ownership of ETF Shares will be shown on the records of the broker through which you hold the shares. Vanguard will not have any record of your ownership. Your account information will be maintained by your broker, which will provide you with account statements, confirmations of your purchases and sales of ETF Shares, and tax information. Your broker also will be responsible for ensuring that you receive income and capital gains distributions, as well as shareholder reports and other communications from the fund whose ETF Shares you own. You will receive other services (e.g., dividend reinvestment and average cost information) only if your broker offers these services.

9

Investing in Index Funds

What Is Indexing?

Indexing is an investment strategy for tracking the performance of a specified market benchmark, or "index." An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market.

There are many types of indexes. Some represent entire markets—such as the U.S. stock market or the U.S. bond market. Other indexes cover market segments—such as small-capitalization stocks or short-term bonds. One cannot invest directly in an index.

The index sponsor determines the securities to include in the index, the weighting of each security in the index, and the appropriate time to make changes to the composition of the index. Generally, the index sponsor does not provide any warranty, or accept any liability, with respect to the quality, accuracy, or completeness of either the target index or its related data. Errors made by the index sponsor may occur from time to time and may not be identified by the index sponsor for a period of time or at all. Vanguard does not provide any warranty or guarantee against such errors. Therefore, the gains, losses, or costs associated with the index sponsor's errors will generally be borne by the index fund and its shareholders.

An index fund seeks to hold all, or a representative sample, of the securities that make up its target index. Index funds attempt to mirror the performance of the target index, for better or worse. However, an index fund generally does not perform exactly like its target index. For example, index funds have operating expenses and transaction costs. Market indexes do not, and therefore they will usually have a slight performance advantage over funds that track them. The ability of an index fund to match its performance to that of its target index can also be impacted by, among other things, the timing and size of cash flows and the size of the fund. Market disruptions and regulatory restrictions could also have an adverse effect on a fund's ability to adjust its exposure to the required levels in order to track the index.

Index funds typically have the following characteristics:

•Variety of investments. Index funds generally invest in the securities of a variety of companies, industries, and government entities.

•Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.

•Low cost. Index funds are generally inexpensive to run compared with actively managed funds. They have low or no research costs and typically keep trading activity—and thus dealer markups and other transaction costs—to a minimum compared with actively managed funds.

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More on the Fund and ETF Shares

This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main principles of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any fund, you should take into account your personal tolerance for

fluctuations in the securities markets. Look for this symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to fund investors, we have provided Plain Talk® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

This prospectus offers the Fund's ETF Shares, an exchange-traded class of shares. A separate prospectus offers the Fund's Investor Shares and AdmiralTM Shares, which generally have investment minimums of $3,000. In addition, another prospectus offers the Fund's Institutional Shares, which are generally for investors who invest a minimum of $5 million. Another prospectus offers Institutional Select Shares, which are generally for investors who invest a minimum of $3 billion.

All share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses; as a result, their investment returns will differ.

A Note to Investors

Vanguard ETF Shares can be purchased directly from the issuing Fund only by certain authorized broker-dealers in exchange for a basket of securities (or, in some cases, for cash or a combination of cash and securities). Individual investors generally will not be able to purchase ETF Shares directly from the Fund. Instead, these investors will purchase ETF Shares on the secondary market through a broker.

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Plain Talk About Costs of Investing

Costs are an important consideration in choosing an ETF. That is because you, as a shareholder, pay a proportionate share of the costs of operating a fund and any transaction costs incurred when the fund buys or sells securities. These costs can erode a substantial portion of the gross income or the capital appreciation a fund achieves. Even seemingly small differences in expenses can, over time, have a dramatic effect on a fund's performance.

The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its objective. The Fund's board of trustees, which oversees the Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Note that the Fund's investment objective is not fundamental and may be changed without a shareholder vote. The Fund's policy of investing at least 80% of its assets in securities that are held in its target index may be changed only upon 60 days' notice to shareholders.

Market Exposure

The Fund is subject to interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests in a geographically diverse mix of short-, intermediate-, and long-term bonds.

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Although bonds are often thought to be less risky than stocks, there have been periods when bond prices have fallen significantly because of rising interest rates. For instance, prices of U.S. long-term bonds fell by almost 48% between December 1976 and September 1981. Note that over comparable periods of time, the prices of foreign bonds and U.S. bonds may increase or decrease by different amounts, and in some cases may move in opposite directions.

To illustrate the relationship between bond prices and interest rates, the following table shows the effect of a 1% and a 2% change (both up and down) in interest rates on the values of three noncallable bonds (i.e., bonds that cannot be redeemed by the issuer) of different maturities, each with a face value of $1,000.

1 Assuming a 4% coupon rate.

These figures are for illustration only; you should not regard them as an indication of future performance of foreign bonds generally or the Fund in particular.

Plain Talk About Bonds and Interest Rates

As a rule, when interest rates rise, bond prices fall. The opposite is also true: Bond prices go up when interest rates fall. Why do bond prices and interest rates move in opposite directions? Let's assume that you hold a bond offering a 4% yield. A year later, interest rates are on the rise and bonds of comparable quality and maturity are offered with a 5% yield. With higher-yielding bonds available, you would have trouble selling your 4% bond for the price you paid—you would probably have to lower your asking price. On the other hand, if interest rates were falling and 3% bonds were being offered, you should be able to sell your 4% bond for more than you paid.

Changes in interest rates can affect bond income as well as bond prices.

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The Fund is subject to income risk, which is the chance that the Fund's income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest new cash flow and cash from maturing bonds in lower-yielding bonds. Income risk should be moderate for the Fund because it invests in a diverse mix of short-, intermediate-, and long-term bonds, so investors should expect the Fund's monthly income to fluctuate.

Plain Talk About Bond Maturities

A bond is issued with a specific maturity date—the date when the issuer must pay back the bond's principal (face value). Bond maturities range from less than 1 year to more than 30 years. Typically, the longer a bond's maturity, the more price risk you, as a bond investor, will face as interest rates rise—but also the higher the potential yield you could receive. Longer-term bonds are more suitable for investors willing to take a greater risk of price fluctuations to get higher and more stable interest income. Shorter-term bond investors should be willing to accept lower yields and greater income variability in return for less fluctuation in the value of their investment. The stated maturity of a bond may differ from the effective maturity of a bond, which takes into consideration that an action such as a call or refunding may cause bonds to be repaid before their stated maturity dates.

Although falling interest rates tend to strengthen bond prices, they can cause other problems for bond fund investors—bond calls and prepayments.

The Fund is subject to call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond's call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. Such redemptions and subsequent reinvestments would also increase the Fund's portfolio turnover rate.

Because the Fund invests only a small portion of its assets in callable bonds, call risk should be low for the Fund.

The Fund is subject to credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. Credit risk should be relatively low for the Fund because it purchases only bonds that are of investment-grade quality.

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Although the Fund purchases only investment-grade bonds, a bond held by the Fund may be downgraded, causing the Fund to hold securities below investment-grade. If a bond is downgraded below investment-grade, the Fund will generally attempt to sell the bond within a reasonable period of time. If the Fund determines that the bond cannot be sold at a reasonable price, the Fund may hold the bond until a reasonable price for the bond may be obtained.

Plain Talk About Credit Quality

A bond's credit quality rating is an assessment of the issuer's ability to pay interest on the bond and, ultimately, to repay the principal. The lower the credit quality, the greater the perceived chance that the bond issuer will default, or fail to meet its payment obligations. All things being equal, the lower a bond's credit quality, the higher its yield should be to compensate investors for assuming additional risk.

The Fund is subject to country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign companies, governments, or government agencies. Because the Fund may invest a large portion of its assets in bonds of issuers located in a particular country or region, the Fund's performance may be hurt disproportionately by the poor performance of its investments in that area. Country/regional risk for the Fund is high.

As of October 31, 2019, the target index for the Fund held a substantial percentage of its assets in bonds of issuers located in a small number of markets, as shown in the following table:

Bloomberg Barclays Global Aggregate ex-USD

Float Adjusted RIC Capped Index (USD Hedged)

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The Fund is subject to nondiversification risk, which is the chance that the Fund's performance may be hurt disproportionately by the poor performance of bonds issued by just a few issuers or even a single issuer. The Fund is considered nondiversified, which means that it may invest a significant percentage of its assets in bonds issued by a small number of issuers as compared with diversified mutual funds.

As of October 31, 2019, the target index for the Fund held a substantial percentage of its assets in bonds of a small number of issuers, as shown in the following table:

Bloomberg Barclays Global Aggregate ex-USD

Float Adjusted RIC Capped Index (USD Hedged)

The Fund is subject to currency risk and currency hedging risk. The Fund seeks to mimic the performance of foreign bonds without regard to currency exchange rate fluctuations. To accomplish this goal, the Fund attempts to offset, or hedge, its foreign currency exposure by entering into currency hedging transactions, primarily through the use of foreign currency exchange forward contracts (a type of derivative). However, it generally is not possible to perfectly hedge the Fund's foreign currency exposure. The Fund will decline in value if it underhedges a currency that has weakened or overhedges a currency that has strengthened relative to the U.S. dollar. In addition, the Fund will incur expenses to hedge its foreign currency exposure. By entering into currency hedging transactions, the Fund may eliminate any chance to benefit from favorable fluctuations in relevant currency exchange rates. Currency risk and currency hedging risk for the Fund is low. The Fund's use of foreign currency exchange forward contracts also subjects the Fund to counterparty risk, which is the chance that the counterparty to a currency forward contract with the Fund will be unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

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Plain Talk About International Investing

U.S. investors who invest in foreign securities will encounter risks not typically associated with U.S. companies because foreign stock and bond markets operate differently from the U.S. markets. For instance, foreign companies and governments may not be subject to the same or similar accounting, auditing, legal, tax, and financial reporting standards and practices as U.S. companies and the U.S. government, and their stocks and bonds may not be as liquid as those of similar U.S. entities. In addition, foreign stock exchanges, brokers, companies, bond markets, and dealers may be subject to less government supervision and regulation than their counterparts in the United States. These factors, among others, could negatively affect the returns U.S. investors receive from foreign investments.

Security Selection

Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all, or substantially all, of the bonds held in its target index—which is an indexing strategy called "replication"—the Fund uses index "sampling" techniques to select securities. Using computer programs, the Fund's advisor generally selects a representative sample of securities that approximates the full target index in terms of key risk factors and other characteristics. These factors include country of origin, duration, cash flow, credit quality, and callability of the underlying bonds. Because the Fund does not hold all of the securities in its target index, some of the securities (and issuers) that are held will likely be overweighted (or underweighted) compared with the target index.

The Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

The number of bonds held by the Fund and the number of bonds in the Fund's target index were 6,117 and 10,906, respectively, as of October 31, 2019.

Types of bonds. The Fund seeks to track the investment performance of the Bloomberg Barclays Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged). This Index provides a broad-based measure of the global, investment-grade, fixed-rate debt markets. The Index includes government, government agency, corporate, and securitized non-U.S. investment-grade fixed income investments, all issued in currencies other than the U.S. dollar and with maturities of more than one year. The Index is capped to comply with investment company diversification standards of the Internal Revenue Code, which state that, at the close of each fiscal

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quarter, a fund's (1) exposure to any particular bond issuer may not exceed 25% of the fund's assets and (2) aggregate exposure to issuers that individually constitute 5% or more of the fund may not exceed 50% of the fund's assets. To help enforce these limits, if the Index, on the last business day of any month, were to have greater than 20% exposure to any particular bond issuer, or greater than 48% aggregate exposure to issuers that individually constitute 5% or more of the Index, then the excess would be reallocated to bonds of other issuers represented in the Index. Notwithstanding the fact that the Index is capped, exposure of the Index or the Fund to a particular bond issuer may exceed 25%, and issuers that individually constitute 5% or more of the Index or the Fund may, in the aggregate, constitute more than 50% of the Index or the Fund on any day during the month because of currency and/or price movements.

The Fund will attempt to hedge its foreign currency exposure, primarily through the use of foreign currency exchange forward contracts, in order to correlate to the returns of the Index, which is U.S. dollar hedged. Such hedging is intended to minimize the currency risk associated with investment in bonds denominated in currencies other than the U.S. dollar. Local currency bonds are bonds denominated in the local currency of a non-U.S. country. They can be issued by foreign governments, government agencies, and corporations. To the extent that the Fund owns local currency bonds and hedges its foreign currency exposure, it is subject to currency hedging risk. Currency hedging risk should be low for the Fund. All of the bonds held by the Fund will be local currency bonds.

To the extent that the Fund enters into currency hedging transactions, the Fund is subject to counterparty risk. Counterparty risk is the chance that the counterparty to a currency forward contract with the Fund is unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

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Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index, or a reference rate. The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

•Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

•Add value when these instruments are attractively priced.

•Adjust sensitivity to changes in interest rates.

•Hedge foreign currency exposure.

The Fund's derivative investments may include fixed income futures contracts, fixed income options, interest rate swaps, total return swaps, credit default swaps, or other derivatives. Losses (or gains) involving futures contracts can sometimes be substantial—in part because a relatively small price movement in a futures contract may result in an immediate and substantial loss (or gain) for a fund. Similar risks exist for other types of derivatives.

The Fund will enter into foreign currency exchange forward contracts, which are a type of derivative, in order to hedge its foreign currency exposure. A foreign currency exchange forward contract is an agreement to buy or sell a currency at a specific price on a specific date, usually 30, 60, or 90 days in the future. These contracts will be used in an effort to offset any changes in the dollar value of foreign bonds attributable to changes in the value of the bonds' local currencies relative to the U.S. dollar. Although such contracts can protect the Fund from unfavorable fluctuations in currency exchange rates, they also reduce or eliminate any chance for the Fund to benefit from favorable exchange rate fluctuations. Notably, foreign currency exchange forward contracts do not prevent the Fund's securities from falling in value for reasons unrelated to currency exchange rates, such as interest rate increases and credit downgrades.

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Plain Talk About Derivatives

Derivatives can take many forms. Some forms of derivatives—such as exchange- traded futures and options on securities, commodities, or indexes—have been trading on regulated exchanges for decades. These types of derivatives are standardized contracts that can easily be bought and sold and whose market values are determined and published daily. On the other hand, non-exchange- traded derivatives—such as certain swap agreements and foreign currency exchange forward contracts—tend to be more specialized or complex and may be more difficult to accurately value.

The Fund may invest a small portion of its assets in fixed income futures, which are a type of derivative, and/or shares of exchange-traded funds (ETFs). These fixed income futures and ETFs typically provide returns similar to those of the bonds listed in the index, or in a subset of the index, the Fund seeks to track. The Fund may purchase futures or ETFs when doing so will reduce the Fund's transaction costs, facilitate cash management, mitigate risk, or have the potential to add value because the instruments are favorably priced. Vanguard receives no additional revenue from Fund assets invested in ETF Shares of other Vanguard funds. Fund assets invested in ETF Shares are excluded when allocating to the Fund its share of the costs of Vanguard operations.

Cash Management

The Fund's daily cash balance may be invested in Vanguard Market Liquidity Fund and/ or Vanguard Municipal Cash Management Fund (each, a CMT Fund), which are low- cost money market funds. When investing in a CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a CMT Fund.

Methods Used to Meet Redemption Requests

Redemptions of ETF Shares are typically met through a combination of cash and securities held by the Fund; see "How Are Vanguard ETF Shares Different From Conventional Mutual Fund Shares?" If cash is used to meet redemptions, the Fund typically obtains such cash through positive cash flows or the sale of Fund holdings consistent with the Fund's investment objective and strategy. Please consult the Fund's Statement of Additional Information for further information on redemptions of ETF Shares.

Under certain circumstances, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an

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interfund lending facility or through a bank line-of-credit, including a joint committed credit facility, in order to meet redemption requests.

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund's best interest, so long as the strategy or policy employed is consistent with the Fund's investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange- traded funds that are consistent with the Fund's investment objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately.

Special Risks of Exchange-Traded Shares

ETF Shares are not individually redeemable. They can be redeemed with the issuing Fund at NAV only by certain authorized broker-dealers and only in large blocks known as Creation Units. Consequently, if you want to liquidate some or all of your ETF Shares, you must sell them on the secondary market at prevailing market prices.

The market price of ETF Shares may differ from NAV. Although it is expected that the market price of an ETF Share typically will approximate its NAV, there may be times when the market price and the NAV differ significantly. Thus, you may pay more (premium) or less (discount) than NAV when you buy ETF Shares on the secondary market, and you may receive more or less than NAV when you sell those shares. These discounts and premiums are likely to be greatest during times of market disruption or extreme market volatility.

Vanguard's website at vanguard.com shows the previous day's closing NAV and closing market price for the Fund's ETF Shares. The website also discloses, in the Premium/Discount Analysis section of the ETF Shares' Price & Performance page, how frequently the Fund's ETF Shares traded at a premium or discount to NAV (based on closing NAVs and market prices) and the magnitudes of such premiums

and discounts.

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An active trading market may not exist. Although Vanguard ETF Shares are listed on a national securities exchange, it is possible that an active trading market may not be maintained. Although this could happen at any time, it is more likely to occur during times of severe market disruption. If you attempt to sell your ETF Shares when an active trading market is not functioning, you may have to sell at a significant discount to NAV. In extreme cases, you may not be able to sell your shares at all.

Trading may be halted. Trading of Vanguard ETF Shares on an exchange may be halted by the activation of individual or marketwide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). Trading of ETF Shares may also be halted if (1) the shares are delisted from the listing exchange without first being listed on another exchange or (2) exchange officials determine that such action is appropriate in the interest of a fair and orderly market or for the protection of investors.

Conversion Privilege

Owners of conventional shares issued by the Fund may convert those shares to ETF Shares of equivalent value of the same fund. Please note that investors who own conventional shares through a 401(k) plan or other employer-sponsored retirement or benefit plan generally may not convert those shares to ETF Shares and should check with their plan sponsor or recordkeeper. ETF Shares, whether acquired through a conversion or purchased on the secondary market, cannot be converted to conventional shares by a shareholder. Also, ETF Shares of one fund cannot be exchanged for ETF Shares of another fund.

You must hold ETF Shares in a brokerage account. Thus, before converting conventional shares to ETF Shares, you must have an existing, or open a new, brokerage account. This account may be with Vanguard Brokerage Services® or with any other brokerage firm. To initiate a conversion of conventional shares to ETF Shares, please contact your broker.

Vanguard Brokerage Services does not impose a fee on conversions from Vanguard conventional shares to Vanguard ETF Shares. However, other brokerage firms may charge a fee to process a conversion. Vanguard reserves the right, in the future, to impose a transaction fee on conversions or to limit, temporarily suspend, or terminate the conversion privilege.

Converting conventional shares to ETF Shares is generally accomplished as follows. First, after your broker notifies Vanguard of your request to convert, Vanguard will transfer your conventional shares from your account to the broker's omnibus account with Vanguard (an account maintained by the broker on behalf of all its customers who hold conventional Vanguard fund shares through the broker). After the transfer,

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Vanguard's records will reflect your broker, not you, as the owner of the shares. Next, your broker will instruct Vanguard to convert the appropriate number or dollar amount of conventional shares in its omnibus account to ETF Shares of equivalent value, based on the respective NAVs of the two share classes.

Your Fund's transfer agent will reflect ownership of all ETF Shares in the name of the Depository Trust Company (DTC). The DTC will keep track of which ETF Shares belong to your broker, and your broker, in turn, will keep track of which ETF Shares belong to you.

Because the DTC is unable to handle fractional shares, only whole shares can be converted. For example, if you owned 300.25 conventional shares, and this was equivalent in value to 90.75 ETF Shares, the DTC account would receive 90 ETF Shares. Conventional shares with a value equal to 0.75 ETF Shares (in this example, that would be 2.481 conventional shares) would remain in the broker's omnibus account with Vanguard. Your broker then could either (1) credit your account with 0.75 ETF Shares or (2) redeem the 2.481 conventional shares for cash at NAV and deliver that cash to your account. If your broker chose to redeem your conventional shares, you would realize a gain or loss on the redemption that must be reported on your tax return (unless you hold the shares in an IRA or other tax-deferred account). Please consult your broker for information on how it will handle the conversion process, including whether it will impose a fee to process a conversion.

If you convert your conventional shares to ETF Shares through Vanguard Brokerage Services, all conventional shares for which you request conversion will be converted to ETF Shares of equivalent value. Because no fractional shares will have to be sold, the transaction will not be taxable.

Here are some important points to keep in mind when converting conventional shares of a Vanguard fund to ETF Shares:

•The conversion process can take anywhere from several days to several weeks, depending on your broker. Vanguard generally will process conversion requests either on the day they are received or on the next business day. Vanguard imposes conversion blackout windows around the dates when a fund with ETF Shares declares dividends. This is necessary to prevent a shareholder from collecting a dividend from both the conventional share class currently held and also from the ETF share class to which the shares will be converted.

•Until the conversion process is complete, you will remain fully invested in a fund's conventional shares, and your investment will increase or decrease in value in tandem with the NAV of those shares.

•The conversion transaction is nontaxable except, if applicable, to the very limited extent previously described.

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A precautionary note to investment companies: Vanguard ETF Shares are issued by registered investment companies, and therefore the acquisition of such shares by other investment companies is subject to the restrictions of Section 12(d)(1) of the Investment Company Act of 1940. Vanguard has obtained an SEC exemptive order that allows registered investment companies to invest in the issuing funds beyond the limits of Section 12(d)(1), subject to certain terms and conditions, including the requirement to enter into a participation agreement with Vanguard.

Frequent Trading and Market-Timing

Unlike frequent trading of a Vanguard fund's conventional (i.e., not exchange-traded) classes of shares, frequent trading of ETF Shares does not disrupt portfolio management or otherwise harm fund shareholders. The vast majority of trading in ETF Shares occurs on the secondary market. Because these trades do not involve the issuing fund, they do not harm the fund or its shareholders. Certain broker-dealers are authorized to purchase and redeem ETF Shares directly with the issuing fund. Because these trades typically are effected in kind (i.e., for securities and not for cash), or are assessed a transaction fee when effected in cash, they do not cause any of the harmful effects to the issuing fund (as previously noted) that may result from frequent trading. For these reasons, the board of trustees of each fund that issues ETF Shares has determined that it is not necessary to adopt policies and procedures to detect and deter frequent trading and market-timing of ETF Shares.

Portfolio Holdings

Please consult the Fund's Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund's portfolio holdings.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests from shareholders of conventional (not exchange- traded) shares or to changes in the composition of its target index or in an effort to manage the fund's duration. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A turnover rate of 100%, for example, would mean that the Fund had sold and replaced securities valued at 100% of its net assets within a one-year period. In general, the greater the turnover rate, the greater the impact transaction costs will have on a fund's return. Also, funds with high turnover rates may be more likely to generate capital gains, including short-term capital gains, that must be distributed to shareholders and will be taxable to shareholders investing through a taxable account.

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The Fund and Vanguard

The Fund is a member of The Vanguard Group, a family of over 200 funds. All of the funds that are members of The Vanguard Group (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although fund shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds' marketing costs.

Plain Talk About Vanguard's Unique Corporate Structure

The Vanguard Group is owned jointly by the funds it oversees and thus indirectly by the shareholders in those funds. Most other mutual funds are operated by management companies that are owned by third parties—either public or private stockholders—and not by the funds they serve.

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For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended April 30.

The manager primarily responsible for the day-to-day management of the Fund is:

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard's Fixed Income Indexing Americas. He has been with Vanguard since 1998, has worked in investment management since 1999, has managed investment portfolios since 2005, and has managed the Fund since its inception in 2013. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

The Fund's Statement of Additional Information provides information about the portfolio manager's compensation, other accounts under management, and ownership of shares of the Fund.

Dividends, Capital Gains, and Taxes

Fund Distributions

The Fund distributes to shareholders virtually all of its net income (interest less expenses) as well as any net short-term or long-term capital gains realized from the sale of its holdings. Income dividends generally are declared monthly and distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

Plain Talk About Distributions

As a shareholder, you are entitled to your portion of a fund's income from interest as well as capital gains from the fund's sale of investments. Income consists of interest the fund earns from its money market and bond investments. Capital gains are realized whenever the fund sells securities for higher prices than it paid for them. These capital gains are either short-term or long-term, depending on whether the fund held the securities for one year or less or for more than one year.

Reinvestment of Distributions

In order to reinvest dividend and capital gains distributions, investors in the Fund's ETF Shares must hold their shares at a broker that offers a reinvestment service. This can be the broker's own service or a service made available by a third party, such as the broker's outside clearing firm or the DTC. If a reinvestment service is available, distributions of income and capital gains can automatically be reinvested in additional

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whole and fractional ETF Shares of the Fund. If a reinvestment service is not available, investors will receive their distributions in cash. To determine whether a reinvestment service is available and whether there is a commission or other charge for using this service, consult your broker.

As with all exchange-traded funds, reinvestment of dividend and capital gains distributions in additional ETF Shares will occur four business days or more after the ex-dividend date (the date when a distribution of dividends or capital gains is deducted from the price of the Fund's shares). The exact number of days depends on your broker. During that time, the amount of your distribution will not be invested in the Fund and therefore will not share in the Fund's income, gains, and losses.

Basic Tax Points

Investors in taxable accounts should be aware of the following basic federal income tax points:

•Distributions are taxable to you whether or not you reinvest these amounts in additional ETF Shares.

•Distributions declared in December—if paid to you by the end of January—are taxable as if received in December.

•Any income dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income.

•Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned ETF Shares.

•Income and capital gains distributions may vary considerably from month to month or year to year, as applicable, as a result of the Fund's normal investment and currency hedging activities and cash flows.

•A sale of ETF Shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on "net investment income." Net investment income takes into account distributions paid by the Fund and capital gains from any sale of ETF Shares.

Income dividends and capital gains distributions that you receive, as well as your gains or losses from any sale of ETF Shares, may be subject to state and local income taxes.

The Fund may be subject to foreign taxes or foreign tax withholding on dividends, interest, and some capital gains that it receives on foreign securities. You may qualify for an offsetting credit or deduction under U.S. tax laws for any amount designated as your

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portion of the Fund's foreign tax obligations, provided that you meet certain requirements. See your tax advisor or IRS publications for more information.

This prospectus provides general tax information only. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

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A fund also will use fair-value pricing if the value of a security it holds has been materially affected by events occurring before the fund's pricing time but after the close of the principal exchange or market on which the security is traded. This most commonly occurs with foreign securities, which may trade on foreign exchanges or markets that close many hours before the fund's pricing time. Intervening events might be company-specific (e.g., earnings report, material credit events) or country-specific or regional/global (e.g., natural disaster, economic or political news, act of terrorism, interest rate change). Intervening events include price movements in U.S. markets that exceed a specified threshold or that are otherwise deemed to affect the value of foreign securities. A fund also may use fair-value pricing on bond market holidays when the fund is open for business (such as Columbus Day and Veterans Day).

Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

Vanguard's website will show the previous day's closing NAV and closing market price for the Fund's ETF Shares.

Certain affiliates of the Fund and the advisor may purchase and resell ETF shares pursuant to the prospectus.

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Financial Highlights

Financial highlights information is intended to help you understand a fund's performance for the past five years (or, if shorter, its period of operations). Certain information reflects financial results for a single fund share. Total return represents the rate that an investor would have earned or lost each period on an investment in a fund or share class (assuming reinvestment of all distributions). This information has been obtained from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report, along with fund financial statements, is included in a fund's most recent annual report to shareholders. You may obtain a free copy of a fund's latest annual or semiannual report, which is available upon request.

1 Calculated based on average shares outstanding.

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CFA® is a registered trademark owned by CFA Institute.

BLOOMBERG is a trademark and service mark of Bloomberg Finance L.P. BARCLAYS is a trademark and service mark of Barclays Bank Plc, used under license. Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL) (collectively, Bloomberg), or Bloomberg's licensors, own all proprietary rights in the Bloomberg Barclays Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged) (the Indices or Bloomberg Barclays Indices).

Neither Barclays Bank Plc, Barclays Capital Inc., or any affiliate (collectively Barclays) or Bloomberg is the issuer or producer of the Total International Bond ETF and neither Bloomberg nor Barclays has any responsibilities, obligations or duties to investors in the Total International Bond ETF. The Indices is licensed for use by The Vanguard Group, Inc. (Vanguard) as the sponsor of the Total International Bond ETF. Bloomberg and Barclays' only relationship with Vanguard in respect to the Indices is the licensing of the Indices, which is determined, composed and calculated by BISL, or any successor thereto, without regard to the Issuer or the Total International Bond ETF or the owners of the Total International Bond ETF.

Additionally, Vanguard may for itself execute transaction(s) with Barclays in or relating to the Indices in connection with the Total International Bond ETF. Investors acquire the Total International Bond ETF from Vanguard and investors neither acquire any interest in the Indices nor enter into any relationship of any kind whatsoever with Bloomberg or Barclays upon making an investment in the Total International Bond ETF. The Total International Bond ETF is not sponsored, endorsed, sold or promoted by Bloomberg or Barclays. Neither Bloomberg nor Barclays makes any representation or warranty, express or implied regarding the advisability of investing in the Total International Bond ETF or the advisability of investing in securities generally or the ability of the Indices to track corresponding or relative market performance. Neither Bloomberg nor Barclays has passed on the legality or suitability of the Total International Bond ETF with respect to any person or entity. Neither Bloomberg nor Barclays is responsible for and has not participated in the determination of the timing of, prices at, or quantities of the Total International Bond ETF to be issued. Neither Bloomberg nor Barclays has any obligation to take the needs of the Issuer or the owners of the Total International Bond ETF or any other third party into consideration in determining, composing or calculating the Indices. Neither Bloomberg nor Barclays has any obligation or liability in connection with administration, marketing or trading of the Total International Bond ETF.

The licensing agreement between Bloomberg and Barclays is solely for the benefit of Bloomberg and Barclays and not for the benefit of the owners of the Total International Bond ETF, investors or other third parties. In addition, the licensing agreement between Vanguard and Bloomberg is solely for the benefit of Vanguard and Bloomberg and not for the benefit of the owners of the Total International Bond ETF, investors or other third parties.

NEITHER BLOOMBERG NOR BARCLAYS SHALL HAVE ANY LIABILITY TO THE ISSUER, INVESTORS OR TO OTHER THIRD PARTIES FOR THE QUALITY, ACCURACY AND/OR COMPLETENESS OF THE BLOOMBERG BARCLAYS INDICES OR ANY DATA INCLUDED THEREIN OR FOR INTERRUPTIONS IN THE DELIVERY OF THE BLOOMBERG BARCLAYS INDICES. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE ISSUER, THE INVESTORS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE BLOOMBERG BARCLAYS INDICES OR ANY DATA INCLUDED THEREIN. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY EXPRESS OR IMPLIED WARRANTIES, AND EACH HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE BLOOMBERG BARCLAYS INDICES OR ANY DATA INCLUDED THEREIN. BLOOMBERG RESERVES THE RIGHT TO CHANGE THE METHODS OF CALCULATION OR PUBLICATION, OR TO CEASE THE CALCULATION OR PUBLICATION OF THE BLOOMBERG BARCLAYS INDICES, AND NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY MISCALCULATION OF OR ANY INCORRECT, DELAYED OR INTERRUPTED PUBLICATION WITH RESPECT TO THE BLOOMBERG BARCLAYS INDICES. NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY DAMAGES, INCLUDING, WITHOUT LIMITATION, ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY LOST PROFITS AND EVEN IF ADVISED OF THE POSSIBILITY OF SUCH, RESULTING FROM THE USE OF A BLOOMBERG BARCLAYS INDICES OR ANY DATA INCLUDED THEREIN OR WITH RESPECT TO THE TOTAL INTERNATIONAL BOND ETF.

None of the information supplied by Bloomberg or Barclays and used in this publication may be reproduced in any manner without the prior written permission of both Bloomberg and Barclays Capital, the investment banking division of Barclays Bank Plc. Barclays Bank Plc is registered in England No. 1026167. Registered office 1 Churchill Place London E14 5HP.

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Glossary of Investment Terms

Authorized Participant. Institutional investors that are permitted to purchase Creation Units directly from, and redeem Creation Units directly with, the issuing fund. To be an Authorized Participant, an entity must be a participant in the Depository Trust Company and must enter into an agreement with the fund's Distributor.

Average Maturity. The average length of time until bonds held by a fund reach maturity and are repaid. In general, the longer the average maturity, the more a fund's share price fluctuates in response to changes in market interest rates. In calculating average maturity, a fund uses a bond's maturity or, if applicable, an earlier date on which the advisor believes it is likely that a maturity-shortening device (such as a call, a put, a refunding, a prepayment, or a redemption provision or an adjustable coupon rate) will cause the bond to be repaid.

Bid-Ask Spread. The difference between the price a dealer is willing to pay for a security (the bid price) and the somewhat higher price at which the dealer is willing to sell the same security (the ask price).

Bond. A debt security (IOU) issued by a corporation, a government, or a government agency in exchange for the money the bondholder lends it. In most instances, the issuer agrees to pay back the loan by a specific date and generally to make regular interest payments until that date.

Capital Gains Distributions. Payments to fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Coupon Rate. The interest rate paid by the issuer of a debt security until its maturity. It is expressed as an annual percentage of the face value of the security.

Creation Unit. A large block of a specified number of ETF Shares. Certain broker- dealers known as "Authorized Participants" may purchase and redeem ETF Shares from the issuing fund in Creation Unit size blocks.

Dividend Distributions. Payments to fund shareholders of income from interest or dividends generated by a fund's investments.

Ex-Dividend Date. The date when a distribution of dividends and/or capital gains is deducted from the share price of a mutual fund, ETF, or stock. On the ex-dividend date, the share price drops by the amount of the distribution per share (plus or minus any market activity).

Expense Ratio. A fund's total annual operating expenses expressed as a percentage of the fund's average net assets. The expense ratio includes management and administrative expenses, but it does not include the transaction costs of buying and selling portfolio securities.

Face Value. The amount to be paid at a bond's maturity; also known as the par value or principal.

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Fixed Income Security. An investment, such as a bond, representing a debt that must be repaid by a specified date, and on which the borrower must pay a fixed, variable, or floating rate of interest.

Float-Adjusted Index. An index that weights its constituent securities based on the value of the constituent securities that are available for public trading, rather than the value of all constituent securities. Some portion of an issuer's securities may be unavailable for public trading because, for example, those securities are owned by company insiders on a restricted basis or by a government agency. By excluding unavailable securities, float-adjusted indexes can produce a more accurate picture of the returns actually experienced by investors in the measured market.

Inception Date. The date on which the assets of a fund (or one of its share classes) are first invested in accordance with the fund's investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.

Indexing. A low-cost investment strategy in which a fund attempts to track—rather than outperform—a specified market benchmark, or "index."

Investment-Grade Bond. A debt security whose credit quality is considered by independent bond rating agencies, or through independent analysis conducted by a fund's advisor, to be sufficient to ensure timely payment of principal and interest under current economic circumstances. Debt securities rated in one of the four highest rating categories are considered investment-grade. Other debt securities may be considered by an advisor to be investment-grade.

Joint Committed Credit Facility. The Fund participates, along with other funds managed by Vanguard, in a committed credit facility provided by a syndicate of lenders pursuant to a credit agreement that may be renewed annually; each Vanguard fund is individually liable for its borrowings, if any, under the credit facility. The amount and terms of the committed credit facility are subject to approval by the Fund's board of trustees and renegotiation with the lender syndicate on an annual basis.

Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.

New York Stock Exchange (NYSE). A stock exchange based in New York City that is open for regular trading on business days, Monday through Friday, from 9:30 a.m. to 4 p.m., Eastern time.

Principal. The face value of a debt instrument or the amount of money put into an investment.

Securities. Stocks, bonds, money market instruments, and other investments.

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Total Return. A percentage change, over a specified time period, in a fund's net asset value, assuming the reinvestment of all distributions of dividends and capital gains.

Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund's volatility, the wider the fluctuations in its returns.

Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment's price.

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Institutional Division

P.O. Box 2900

Valley Forge, PA 19482-2900

Connect with Vanguard® > vanguard.com

P 3711 022020

Fund Summary

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Example

The following example is intended to help you compare the cost of investing in the Fund's Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 26% of the average value of its portfolio.

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Fund will attempt to hedge its foreign currency exposure, primarily through the use of foreign currency exchange forward contracts, in order to correlate to the returns of the Index, which is U.S. dollar hedged. Such hedging is intended to minimize the currency risk associated with investment in bonds denominated in currencies other than the U.S. dollar.

The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund's investments will be selected through the sampling process and, under normal circumstances, at least 80% of the Fund's assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of October 31, 2019, the dollar-weighted average maturity of the Index was 9.9 years.

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•Credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. Credit risk should be relatively low for the Fund because it purchases only bonds that are of investment-grade quality.

•Call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond's call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. Such redemptions and subsequent reinvestments would also increase the Fund's portfolio turnover rate. Call risk should be low for the Fund because it invests only a small portion of its assets in callable bonds.

•Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

•Currency risk and currency hedging risk. The Fund seeks to mimic the performance of foreign bonds without regard to currency exchange rate fluctuations. To accomplish this goal, the Fund attempts to offset, or hedge, its foreign currency exposure by entering into currency hedging transactions, primarily through the use of foreign currency exchange forward contracts (a type of derivative). However, it generally is not possible to perfectly hedge the Fund's foreign currency exposure. The Fund will decline in value if it underhedges a currency that has weakened or overhedges a currency that has strengthened relative to the U.S. dollar. In addition, the Fund will incur expenses to hedge its foreign currency exposure. By entering into currency hedging transactions, the Fund may eliminate any chance to benefit from favorable fluctuations in relevant currency exchange rates. Currency risk and currency hedging risk for the Fund is low. The Fund's use of foreign currency exchange forward contracts also subjects the Fund to counterparty risk, which is the chance that the counterparty to a currency forward contract with the Fund will be unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

•Derivatives risk. The Fund may invest in derivatives, which may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

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Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund's Institutional Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Institutional Shares compare with those of the Fund's target index, which has investment characteristics similar to those of the Fund. Keep in mind that the Fund's past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

-40%

During the periods shown in the bar chart, the highest return for a calendar quarter was 3.46% (quarter ended March 31, 2016), and the lowest return for a quarter was –2.91% (quarter ended June 30, 2015).

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Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

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Investing in Index Funds

What Is Indexing?

Indexing is an investment strategy for tracking the performance of a specified market benchmark, or "index." An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market.

There are many types of indexes. Some represent entire markets—such as the U.S. stock market or the U.S. bond market. Other indexes cover market segments—such as small-capitalization stocks or short-term bonds. One cannot invest directly in an index.

The index sponsor determines the securities to include in the index, the weighting of each security in the index, and the appropriate time to make changes to the composition of the index. Generally, the index sponsor does not provide any warranty, or accept any liability, with respect to the quality, accuracy, or completeness of either the target index or its related data. Errors made by the index sponsor may occur from time to time and may not be identified by the index sponsor for a period of time or at all. Vanguard does not provide any warranty or guarantee against such errors. Therefore, the gains, losses, or costs associated with the index sponsor's errors will generally be borne by the index fund and its shareholders.

An index fund seeks to hold all, or a representative sample, of the securities that make up its target index. Index funds attempt to mirror the performance of the target index, for better or worse. However, an index fund generally does not perform exactly like its target index. For example, index funds have operating expenses and transaction costs. Market indexes do not, and therefore they will usually have a slight performance advantage over funds that track them. The ability of an index fund to match its performance to that of its target index can also be impacted by, among other things, the timing and size of cash flows and the size of the fund. Market disruptions and regulatory restrictions could also have an adverse effect on a fund's ability to adjust its exposure to the required levels in order to track the index.

Index funds typically have the following characteristics:

•Variety of investments. Index funds generally invest in the securities of a variety of companies, industries, and government entities.

•Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.

•Low cost. Index funds are generally inexpensive to run compared with actively managed funds. They have low or no research costs and typically keep trading activity—and thus dealer markups and other transaction costs—to a minimum compared with actively managed funds.

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More on the Fund

This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main principles of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance

for fluctuations in the securities markets. Look for this symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

This prospectus offers the Fund's Institutional Shares, which are generally for investors who invest a minimum of $5 million. A separate prospectus offers the Fund's Investor Shares and Admiral™ Shares, which generally have investment minimums of $3,000.

Another prospectus offers Institutional Select Shares, which are generally for investors who invest a minimum of $3 billion. In addition, the Fund issues ETF Shares (an exchange-traded class of shares), which are also offered through a separate prospectus.

All share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses; as a result, their investment returns will differ.

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Plain Talk About Costs of Investing

Costs are an important consideration in choosing a mutual fund. That is because you, as a shareholder, pay a proportionate share of the costs of operating a fund and any transaction costs incurred when the fund buys or sells securities. These costs can erode a substantial portion of the gross income or the capital appreciation a fund achieves. Even seemingly small differences in expenses can, over time, have a dramatic effect on a fund's performance.

The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its objective. The Fund's board of trustees, which oversees the Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Note that the Fund's investment objective is not fundamental and may be changed without a shareholder vote. The Fund's policy of investing at least 80% of its assets in securities that are held in its target index may be changed only upon 60 days' notice to shareholders.

Market Exposure

The Fund is subject to interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests in a geographically diverse mix of short-, intermediate-, and long-term bonds.

Although bonds are often thought to be less risky than stocks, there have been periods when bond prices have fallen significantly because of rising interest rates. For instance, prices of U.S. long-term bonds fell by almost 48% between December 1976 and September 1981. Note that over comparable periods of time, the prices of foreign bonds and U.S. bonds may increase or decrease by different amounts, and in some cases may move in opposite directions.

To illustrate the relationship between bond prices and interest rates, the following table shows the effect of a 1% and a 2% change (both up and down) in interest rates on the values of three noncallable bonds (i.e., bonds that cannot be redeemed by the issuer) of different maturities, each with a face value of $1,000.

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1 Assuming a 4% coupon rate.

These figures are for illustration only; you should not regard them as an indication of future performance of foreign bonds generally or the Fund in particular.

Plain Talk About Bonds and Interest Rates

As a rule, when interest rates rise, bond prices fall. The opposite is also true: Bond prices go up when interest rates fall. Why do bond prices and interest rates move in opposite directions? Let's assume that you hold a bond offering a 4% yield. A year later, interest rates are on the rise and bonds of comparable quality and maturity are offered with a 5% yield. With higher-yielding bonds available, you would have trouble selling your 4% bond for the price you paid—you would probably have to lower your asking price. On the other hand, if interest rates were falling and 3% bonds were being offered, you should be able to sell your 4% bond for more than you paid.

Changes in interest rates can affect bond income as well as bond prices.

The Fund is subject to income risk, which is the chance that the Fund's income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest new cash flow and cash from maturing bonds in lower-yielding bonds. Income risk should be moderate for the Fund because it invests in a diverse mix of short-, intermediate-, and long-term bonds, so investors should expect the Fund's monthly income to fluctuate.

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Plain Talk About Bond Maturities

A bond is issued with a specific maturity date—the date when the issuer must pay back the bond's principal (face value). Bond maturities range from less than 1 year to more than 30 years. Typically, the longer a bond's maturity, the more price risk you, as a bond investor, will face as interest rates rise—but also the higher the potential yield you could receive. Longer-term bonds are more suitable for investors willing to take a greater risk of price fluctuations to get higher and more stable interest income. Shorter-term bond investors should be willing to accept lower yields and greater income variability in return for less fluctuation in the value of their investment. The stated maturity of a bond may differ from the effective maturity of a bond, which takes into consideration that an action such as a call or refunding may cause bonds to be repaid before their stated maturity dates.

Although falling interest rates tend to strengthen bond prices, they can cause other problems for bond fund investors—bond calls and prepayments.

The Fund is subject to call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond's call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. Such redemptions and subsequent reinvestments would also increase the Fund's portfolio turnover rate.

Because the Fund invests only a small portion of its assets in callable bonds, call risk should be low for the Fund.

The Fund is subject to credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. Credit risk should be relatively low for the Fund because it purchases only bonds that are of investment-grade quality.

Although the Fund purchases only investment-grade bonds, a bond held by the Fund may be downgraded, causing the Fund to hold securities below investment-grade. If a bond is downgraded below investment-grade, the Fund will generally attempt to sell the bond within a reasonable period of time. If the Fund determines that the bond cannot be sold at a reasonable price, the Fund may hold the bond until a reasonable price for the bond may be obtained.

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Plain Talk About Credit Quality

A bond's credit quality rating is an assessment of the issuer's ability to pay interest on the bond and, ultimately, to repay the principal. The lower the credit quality, the greater the perceived chance that the bond issuer will default, or fail to meet its payment obligations. All things being equal, the lower a bond's credit quality, the higher its yield should be to compensate investors for assuming additional risk.

The Fund is subject to country/regional risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by foreign companies, governments, or government agencies. Because the Fund may invest a large portion of its assets in bonds of issuers located in a particular country or region, the Fund's performance may be hurt disproportionately by the poor performance of its investments in that area. Country/regional risk for the Fund is high.

As of October 31, 2019, the target index for the Fund held a substantial percentage of its assets in bonds of issuers located in a small number of markets, as shown in the following table:

Bloomberg Barclays Global Aggregate ex-USD

Float Adjusted RIC Capped Index (USD Hedged)

The Fund is subject to nondiversification risk, which is the chance that the Fund's performance may be hurt disproportionately by the poor performance of bonds issued by just a few issuers or even a single issuer. The Fund is considered nondiversified, which means that it may invest a significant percentage of its assets in bonds issued by a small number of issuers as compared with diversified mutual funds.

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As of October 31, 2019, the target index for the Fund held a substantial percentage of its assets in bonds of a small number of issuers, as shown in the following table:

Bloomberg Barclays Global Aggregate ex-USD

Float Adjusted RIC Capped Index (USD Hedged)

The Fund is subject to currency risk and currency hedging risk. The Fund seeks to mimic the performance of foreign bonds without regard to currency exchange rate fluctuations. To accomplish this goal, the Fund attempts to offset, or hedge, its foreign currency exposure by entering into currency hedging transactions, primarily through the use of foreign currency exchange forward contracts (a type of derivative). However, it generally is not possible to perfectly hedge the Fund's foreign currency exposure. The Fund will decline in value if it underhedges a currency that has weakened or overhedges a currency that has strengthened relative to the U.S. dollar. In addition, the Fund will incur expenses to hedge its foreign currency exposure. By entering into currency hedging transactions, the Fund may eliminate any chance to benefit from favorable fluctuations in relevant currency exchange rates. Currency risk and currency hedging risk for the Fund is low. The Fund's use of foreign currency exchange forward contracts also subjects the Fund to counterparty risk, which is the chance that the counterparty to a currency forward contract with the Fund will be unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

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Plain Talk About International Investing

U.S. investors who invest in foreign securities will encounter risks not typically associated with U.S. companies because foreign stock and bond markets operate differently from the U.S. markets. For instance, foreign companies and governments may not be subject to the same or similar accounting, auditing, legal, tax, and financial reporting standards and practices as U.S. companies and the U.S. government, and their stocks and bonds may not be as liquid as those of similar U.S. entities. In addition, foreign stock exchanges, brokers, companies, bond markets, and dealers may be subject to less government supervision and regulation than their counterparts in the United States. These factors, among others, could negatively affect the returns U.S. investors receive from foreign investments.

Security Selection

Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all, or substantially all, of the bonds held in its target index—which is an indexing strategy called "replication"—the Fund uses index "sampling" techniques to select securities. Using computer programs, the Fund's advisor generally selects a representative sample of securities that approximates the full target index in terms of key risk factors and other characteristics. These factors include country of origin, duration, cash flow, credit quality, and callability of the underlying bonds. Because the Fund does not hold all of the securities in its target index, some of the securities (and issuers) that are held will likely be overweighted (or underweighted) compared with the target index.

The Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

The number of bonds held by the Fund and the number of bonds in the Fund's target index were 6,117 and 10,906, respectively, as of October 31, 2019.

Types of bonds. The Fund seeks to track the investment performance of the Bloomberg Barclays Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged). This Index provides a broad-based measure of the global, investment-grade, fixed-rate debt markets. The Index includes government, government agency, corporate, and securitized non-U.S. investment-grade fixed income investments, all issued in currencies other than the U.S. dollar and with maturities of more than one year. The Index is capped to comply with investment company diversification standards of the Internal Revenue Code, which state that, at the close of each fiscal

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quarter, a fund's (1) exposure to any particular bond issuer may not exceed 25% of the fund's assets and (2) aggregate exposure to issuers that individually constitute 5% or more of the fund may not exceed 50% of the fund's assets. To help enforce these limits, if the Index, on the last business day of any month, were to have greater than 20% exposure to any particular bond issuer, or greater than 48% aggregate exposure to issuers that individually constitute 5% or more of the Index, then the excess would be reallocated to bonds of other issuers represented in the Index. Notwithstanding the fact that the Index is capped, exposure of the Index or the Fund to a particular bond issuer may exceed 25%, and issuers that individually constitute 5% or more of the Index or the Fund may, in the aggregate, constitute more than 50% of the Index or the Fund on any day during the month because of currency and/or price movements.

The Fund will attempt to hedge its foreign currency exposure, primarily through the use of foreign currency exchange forward contracts, in order to correlate to the returns of the Index, which is U.S. dollar hedged. Such hedging is intended to minimize the currency risk associated with investment in bonds denominated in currencies other than the U.S. dollar. Local currency bonds are bonds denominated in the local currency of a non-U.S. country. They can be issued by foreign governments, government agencies, and corporations. To the extent that the Fund owns local currency bonds and hedges its foreign currency exposure, it is subject to currency hedging risk. Currency hedging risk should be low for the Fund. All of the bonds held by the Fund will be local currency bonds.

To the extent that the Fund enters into currency hedging transactions, the Fund is subject to counterparty risk. Counterparty risk is the chance that the counterparty to a currency forward contract with the Fund is unable or unwilling to meet its financial obligations. Counterparty risk is low for the Fund.

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Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index, or a reference rate. The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

•Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

•Add value when these instruments are attractively priced.

•Adjust sensitivity to changes in interest rates.

•Hedge foreign currency exposure.

The Fund's derivative investments may include fixed income futures contracts, fixed income options, interest rate swaps, total return swaps, credit default swaps, or other derivatives. Losses (or gains) involving futures contracts can sometimes be substantial—in part because a relatively small price movement in a futures contract may result in an immediate and substantial loss (or gain) for a fund. Similar risks exist for other types of derivatives.

The Fund will enter into foreign currency exchange forward contracts, which are a type of derivative, in order to hedge its foreign currency exposure. A foreign currency exchange forward contract is an agreement to buy or sell a currency at a specific price on a specific date, usually 30, 60, or 90 days in the future. These contracts will be used in an effort to offset any changes in the dollar value of foreign bonds attributable to changes in the value of the bonds' local currencies relative to the U.S. dollar. Although such contracts can protect the Fund from unfavorable fluctuations in currency exchange rates, they also reduce or eliminate any chance for the Fund to benefit from favorable exchange rate fluctuations. Notably, foreign currency exchange forward contracts do not prevent the Fund's securities from falling in value for reasons unrelated to currency exchange rates, such as interest rate increases and credit downgrades.

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Plain Talk About Derivatives

Derivatives can take many forms. Some forms of derivatives—such as exchange- traded futures and options on securities, commodities, or indexes—have been trading on regulated exchanges for decades. These types of derivatives are standardized contracts that can easily be bought and sold and whose market values are determined and published daily. On the other hand, non-exchange- traded derivatives—such as certain swap agreements and foreign currency exchange forward contracts—tend to be more specialized or complex and may be more difficult to accurately value.

The Fund may invest a small portion of its assets in fixed income futures, which are a type of derivative, and/or shares of exchange-traded funds (ETFs). These fixed income futures and ETFs typically provide returns similar to those of the bonds listed in the index, or in a subset of the index, the Fund seeks to track. The Fund may purchase futures or ETFs when doing so will reduce the Fund's transaction costs, facilitate cash management, mitigate risk, or have the potential to add value because the instruments are favorably priced. Vanguard receives no additional revenue from Fund assets invested in ETF Shares of other Vanguard funds. Fund assets invested in ETF Shares are excluded when allocating to the Fund its share of the costs of Vanguard operations.

Cash Management

The Fund's daily cash balance may be invested in Vanguard Market Liquidity Fund and/ or Vanguard Municipal Cash Management Fund (each, a CMT Fund), which are low- cost money market funds. When investing in a CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a CMT Fund.

Methods Used to Meet Redemption Requests

Under normal circumstances, the Fund typically expects to meet redemptions with positive cash flows. When this is not an option, the Fund seeks to maintain its risk exposure by selling a cross section of the Fund's holdings to meet redemptions, while also factoring in transaction costs. Additionally, the Fund may work with larger clients to implement their redemptions in a manner that is least disruptive to the portfolio; see "Potentially disruptive redemptions" under Redeeming Shares in the Investing With Vanguard section.

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Under certain circumstances, including under stressed market conditions, there are additional tools that the Fund may use in order to meet redemptions, including advancing the settlement of market trades with counterparties to match investor redemption payments or delaying settlement of an investor's transaction to match trade settlement within regulatory requirements. The Fund may also suspend payment of redemption proceeds for up to seven days; see "Emergency circumstances" under Redeeming Shares in the Investing With Vanguard section. Additionally under these unusual circumstances, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility or through a bank line-of-credit, including a joint committed credit facility, in order to meet redemption requests.

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund's best interest, so long as the strategy or policy employed is consistent with the Fund's investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange- traded funds that are consistent with the Fund's investment objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately.

Frequent Trading or Market-Timing

Background. Some investors try to profit from strategies involving frequent trading of mutual fund shares, such as market-timing. For funds holding foreign securities, investors may try to take advantage of an anticipated difference between the price of the fund's shares and price movements in overseas markets, a practice also known as time-zone arbitrage. Investors also may try to engage in frequent trading of funds holding investments such as small-cap stocks and high-yield bonds. As money is shifted into and out of a fund by a shareholder engaging in frequent trading, the fund incurs costs for buying and selling securities, resulting in increased brokerage and administrative costs. These costs are borne by all fund shareholders, including the long-term investors who do not generate the costs. In addition, frequent trading may interfere with an advisor's ability to efficiently manage the fund.

Policies to address frequent trading. The Vanguard funds (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation- Protected Securities Index Fund) do not knowingly accommodate frequent trading. The board of trustees of each Vanguard fund (other than money market funds and short- term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) has adopted policies and procedures reasonably designed to detect and discourage frequent trading and, in some cases, to compensate the fund for the costs

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associated with it. These policies and procedures do not apply to ETF Shares because frequent trading in ETF Shares generally does not disrupt portfolio management or otherwise harm fund shareholders. Although there is no assurance that Vanguard will be able to detect or prevent frequent trading or market-timing in all circumstances, the following policies have been adopted to address these issues:

•Each Vanguard fund reserves the right to reject any purchase request—including exchanges from other Vanguard funds—without notice and regardless of size. For example, a purchase request could be rejected because the investor has a history of frequent trading or if Vanguard determines that such purchase may negatively affect a fund's operation or performance.

•Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) generally prohibits, except as otherwise noted in the Investing With Vanguard section, an investor's purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account.

•Certain Vanguard funds charge shareholders purchase and/or redemption fees on transactions.

See the Investing With Vanguard section of this prospectus for further details on Vanguard's transaction policies.

Each Vanguard fund (other than retail and government money market funds), in determining its net asset value, will use fair-value pricing when appropriate, as described in the Share Price section. Fair-value pricing may reduce or eliminate the profitability of certain frequent-trading strategies.

Do not invest with Vanguard if you are a market-timer.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests from shareholders of conventional (not exchange- traded) shares or to changes in the composition of its target index or in an effort to manage the fund's duration. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A turnover rate of 100%, for example, would mean that the Fund had sold and replaced securities valued at 100% of its net assets within a one-year period. In general, the greater the turnover rate, the greater the impact transaction costs will have on a fund's return. Also, funds with high turnover rates may be more likely to generate capital gains, including short-term capital gains, that must be distributed to shareholders and will be taxable to shareholders investing through a taxable account.

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The Fund and Vanguard

The Fund is a member of The Vanguard Group, a family of over 200 funds. All of the funds that are members of The Vanguard Group (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although fund shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds' marketing costs.

Plain Talk About Vanguard's Unique Corporate Structure

The Vanguard Group is owned jointly by the funds it oversees and thus indirectly by the shareholders in those funds. Most other mutual funds are operated by management companies that are owned by third parties—either public or private stockholders—and not by the funds they serve.

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For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended April 30.

The manager primarily responsible for the day-to-day management of the Fund is:

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard's Fixed Income Indexing Americas. He has been with Vanguard since 1998, has worked in investment management since 1999, has managed investment portfolios since 2005, and has managed the Fund since its inception in 2013. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

The Fund's Statement of Additional Information provides information about the portfolio manager's compensation, other accounts under management, and ownership of shares of the Fund.

Dividends, Capital Gains, and Taxes

Fund Distributions

The Fund distributes to shareholders virtually all of its net income (interest less expenses) as well as any net short-term or long-term capital gains realized from the sale of its holdings. Income dividends generally are declared monthly and distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

You can receive distributions of income or capital gains in cash, or you can have them automatically reinvested in more shares of the Fund. However, if you are investing through an employer-sponsored retirement or savings plan, your distributions will be automatically reinvested in additional Fund shares.

Plain Talk About Distributions

As a shareholder, you are entitled to your portion of a fund's income from interest as well as capital gains from the fund's sale of investments. Income consists of interest the fund earns from its money market and bond investments. Capital gains are realized whenever the fund sells securities for higher prices than it paid for them. These capital gains are either short-term or long-term, depending on whether the fund held the securities for one year or less or for more than one year.

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Basic Tax Points

Investors in taxable accounts should be aware of the following basic federal income tax points:

•Distributions are taxable to you whether or not you reinvest these amounts in additional Fund shares.

•Distributions declared in December—if paid to you by the end of January—are taxable as if received in December.

•Any income dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income.

•Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned shares in the Fund.

•Income and capital gains distributions may vary considerably from month to month or year to year, as applicable, as a result of the Fund's normal investment and currency hedging activities and cash flows.

•A sale or exchange of Fund shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

•Any conversion between classes of shares of the same fund is a nontaxable event. By contrast, an exchange between classes of shares of different funds is a taxable event.

•Vanguard (or your intermediary) will send you a statement each year showing the tax status of all of your distributions.

Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on "net investment income." Net investment income takes into account distributions paid by the Fund and capital gains from any sale or exchange of Fund shares.

Income dividends and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes.

The Fund may be subject to foreign taxes or foreign tax withholding on dividends, interest, and some capital gains that it receives on foreign securities. You may qualify for an offsetting credit or deduction under U.S. tax laws for any amount designated as your portion of the Fund's foreign tax obligations, provided that you meet certain requirements. See your tax advisor or IRS publications for more information.

This prospectus provides general tax information only. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

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General Information

Backup withholding. By law, Vanguard must withhold 24% of any taxable distributions or redemptions from your account if you do not:

•Provide your correct taxpayer identification number.

•Certify that the taxpayer identification number is correct.

•Confirm that you are not subject to backup withholding.

Similarly, Vanguard (or your intermediary) must withhold taxes from your account if the IRS instructs us to do so.

Foreign investors. Vanguard funds offered for sale in the United States (Vanguard U.S. funds), including the Fund offered in this prospectus, are not widely available outside the United States. Non-U.S. investors should be aware that U.S. withholding and estate taxes and certain U.S. tax reporting requirements may apply to any investments in Vanguard U.S. funds. Foreign investors should visit the non-U.S. investors page on our website at vanguard.com for information on Vanguard's non-U.S. products.

Invalid addresses. If an income dividend distribution or capital gains distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest the distribution and all future distributions until you provide us with a valid mailing address. Reinvestments will receive the net asset value calculated on the date of the reinvestment.

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not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security).

The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE. The values of any mutual fund shares, including institutional money market fund shares, held by a fund are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a fund are based on the market value of the shares.

A fund also will use fair-value pricing if the value of a security it holds has been materially affected by events occurring before the fund's pricing time but after the close of the principal exchange or market on which the security is traded. This most commonly occurs with foreign securities, which may trade on foreign exchanges or markets that close many hours before the fund's pricing time. Intervening events might be company- specific (e.g., earnings report, material credit events) or country-specific or regional/ global (e.g., natural disaster, economic or political news, act of terrorism, interest rate change). Intervening events include price movements in U.S. markets that exceed a specified threshold or that are otherwise deemed to affect the value of foreign securities. A fund may also use fair-value pricing on bond market holidays when the fund is open for business (such as Columbus Day and Veterans Day).

Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

Vanguard fund share prices are published daily on our website at vanguard.com/prices.

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Financial Highlights

Financial highlights information is intended to help you understand a fund's performance for the past five years (or, if shorter, its period of operations). Certain information reflects financial results for a single fund share. Total return represents the rate that an investor would have earned or lost each period on an investment in a fund or share class (assuming reinvestment of all distributions). This information has been obtained from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report, along with fund financial statements, is included in a fund's most recent annual report to shareholders. You may obtain a free copy of a fund's latest annual or semiannual report, which is available upon request.

1 Calculated based on average shares outstanding.

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Investing With Vanguard

This section of the prospectus explains the basics of doing business with Vanguard. Vanguard fund shares can be held directly with Vanguard or indirectly through an intermediary, such as a bank, a broker, or an investment advisor. If you hold Vanguard fund shares directly with Vanguard, you should carefully read each topic within this section that pertains to your relationship with Vanguard. If you hold Vanguard fund shares indirectly through an intermediary (including shares held in a brokerage account through Vanguard Brokerage Services®), please see Investing With Vanguard Through Other Firms, and also refer to your account agreement with the intermediary for information about transacting in that account. If you hold Vanguard fund shares through an employer-sponsored retirement or savings plan, please see Employer-Sponsored Plans. Vanguard reserves the right to change the following policies without notice. Please call or check online for current information. See Contacting Vanguard.

For Vanguard fund shares held directly with Vanguard, each fund you hold in an account is a separate "fund account." For example, if you hold three funds in a nonretirement account titled in your own name, two funds in a nonretirement account titled jointly with your spouse, and one fund in an individual retirement account, you have six fund accounts—and this is true even if you hold the same fund in multiple accounts. Note that each reference to "you" in this prospectus applies to any one or more registered account owners or persons authorized to transact on your account.

Purchasing Shares

Vanguard reserves the right, without notice, to increase or decrease the minimum amount required to open, convert shares to, or maintain a fund account or to add to an existing fund account.

Investment minimums may differ for certain categories of investors.

Account Minimums for Institutional Shares

To open and maintain an account. $5 million. If you request Institutional Shares when you open a new account but the investment amount does not meet the account minimum for Institutional Shares, your investment will be placed in another share class of the Fund, as appropriate.

Certain Vanguard institutional clients may meet the minimum investment amount by aggregating separate accounts within the same Fund. This aggregation policy does not apply to financial intermediaries.

Vanguard may charge additional recordkeeping fees for institutional clients whose accounts are recordkept by Vanguard. Please contact your Vanguard representative to determine whether additional recordkeeping fees apply to your account.

To add to an existing account. Generally $1.

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How to Initiate a Purchase Request

Be sure to check Exchanging Shares, Frequent-Trading Limitations, and Other Rules You Should Know before placing your purchase request.

Online. You may open certain types of accounts, request a purchase of shares, and request an exchange through our website or our mobile application if you are registered for online access.

By telephone. You may call Vanguard to begin the account registration process or request that the account-opening forms be sent to you. You may also call Vanguard to request a purchase of shares in your account or to request an exchange. See Contacting Vanguard.

By mail. You may send Vanguard your account registration form and check to open a new fund account. To add to an existing fund account, you may send your check with an Invest-by-Mail form (from a transaction confirmation or your account statement) or with a deposit slip (available online).

How to Pay for a Purchase

By electronic bank transfer. You may purchase shares of a Vanguard fund through an electronic transfer of money from a bank account. To establish the electronic bank transfer service on an account, you must designate the bank account online, complete a form, or fill out the appropriate section of your account registration form. After the service is set up on your account, you can purchase shares by electronic bank transfer on a regular schedule (Automatic Investment Plan) or upon request. Your purchase request can be initiated online (if you are registered for online access), by telephone, or by mail.

By wire. Wiring instructions vary for different types of purchases. Please call Vanguard for instructions and policies on purchasing shares by wire. See Contacting Vanguard.

By check. You may make initial or additional purchases to your fund account by sending a check with a deposit slip or by utilizing our mobile application if you are registered for online access. Also see How to Initiate a Purchase Request. Make your check payable to Vanguard and include the appropriate fund number (Vanguard—2011).

By exchange. You may purchase shares of a Vanguard fund using the proceeds from the simultaneous redemption of shares of another Vanguard fund. You may initiate an exchange online (if you are registered for online access), by telephone, or by mail with an exchange form. See Exchanging Shares.

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Trade Date

The trade date for any purchase request received in good order will depend on the day and time Vanguard receives your request, the manner in which you are paying, and the type of fund you are purchasing. Your purchase will be executed using the NAV as calculated on the trade date. See Share Price.

For purchases by check into all funds other than money market funds and for purchases by exchange, wire, or electronic bank transfer into all funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date for the purchase will be the same day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date for the purchase will be the next business day.

For purchases by check into money market funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date for the purchase will be the next business day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date for the purchase will be the second business day following the day Vanguard receives the purchase request. Because money market instruments must be purchased with federal funds and it takes a money market mutual fund one business day to convert check proceeds into federal funds, the trade date for the purchase will be one business day later than for other funds.

If your purchase request is not accurate and complete, it may be rejected. See Other Rules You Should Know—Good Order.

For further information about purchase transactions, consult our website at vanguard.com or see Contacting Vanguard.

Other Purchase Rules You Should Know

Check purchases. All purchase checks must be written in U.S. dollars, be drawn on a U.S. bank, and be accompanied by good order instructions. Vanguard does not accept cash, traveler's checks, starter checks, or money orders. In addition, Vanguard may refuse checks that are not made payable to Vanguard.

New accounts. We are required by law to obtain from you certain personal information that we will use to verify your identity. If you do not provide the information, we may not be able to open your account. If we are unable to verify your identity, Vanguard reserves the right, without notice, to close your account or take such other steps as we deem reasonable. Certain types of accounts may require additional documentation.

Refused or rejected purchase requests. Vanguard reserves the right to stop selling fund shares or to reject any purchase request at any time and without notice, including,

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but not limited to, purchases requested by exchange from another Vanguard fund. This also includes the right to reject any purchase request because the investor has a history of frequent trading or because the purchase may negatively affect a fund's operation or performance.

Large purchases. Call Vanguard before attempting to invest a large dollar amount.

No cancellations. Vanguard will not accept your request to cancel any purchase request once processing has begun. Please be careful when placing a purchase request.

Converting Shares

When a conversion occurs, you receive shares of one class in place of shares of another class of the same fund. At the time of conversion, the dollar value of the "new" shares you receive equals the dollar value of the "old" shares that were converted. In other words, the conversion has no effect on the value of your investment in the fund at the time of the conversion. However, the number of shares you own after the conversion may be greater than or less than the number of shares you owned before the conversion, depending on the NAVs of the two share classes.

Vanguard will not accept your request to cancel any self-directed conversion request once processing has begun. Please be careful when placing a conversion request.

A conversion between share classes of the same fund is a nontaxable event.

Trade Date

The trade date for any conversion request received in good order will depend on the day and time Vanguard receives your request. Your conversion will be executed using the NAVs of the different share classes on the trade date. See Share Price.

For a conversion request (other than a request to convert to ETF Shares) received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. For a conversion request received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day. See Other Rules You Should Know.

Conversions to Institutional Shares

You are eligible for a self-directed conversion from another share class to Institutional Shares of the Fund, provided that your account meets all Institutional Shares' eligibility requirements. You may request a conversion through our website (if you are registered for online access), or you may contact Vanguard by telephone or by mail to request this transaction. Accounts that qualify for Institutional Shares will not be automatically converted.

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Conversions to Institutional Select Shares

You are eligible for a self-directed conversion from another share class to Institutional Select Shares of the Fund, provided that your account meets all eligibility requirements. You may request a conversion through our website (if you are registered for online access), through a trading platform, by mail, or by telephone. Accounts that qualify for Institutional Select Shares will not be automatically converted.

Conversions to ETF Shares

Owners of conventional shares (i.e., not exchange-traded shares) issued by the Fund may convert those shares to ETF Shares of equivalent value of the same fund. Please note that investors who own conventional shares through a 401(k) plan or other employer-sponsored retirement or benefit plan generally may not convert those shares to ETF Shares and should check with their plan sponsor or recordkeeper. ETF Shares, whether acquired through a conversion or purchased on the secondary market, cannot be converted to conventional shares by a shareholder. Also, ETF Shares of one fund cannot be exchanged for ETF Shares of another fund.

ETF Shares must be held in a brokerage account. Thus, before converting conventional shares to ETF Shares, you must have an existing, or open a new, brokerage account. This account may be with Vanguard Brokerage Services or with any other brokerage firm.

Vanguard Brokerage Services does not impose a fee on conversions from conventional shares to Vanguard ETF Shares. However, other brokerage firms may charge a fee to process a conversion. Vanguard reserves the right, in the future, to impose a transaction fee on conversions or to limit, temporarily suspend, or terminate the conversion privilege. For additional information on converting conventional shares to ETF Shares, please contact Vanguard to obtain a prospectus for ETF Shares. See Contacting Vanguard.

Mandatory Conversions to Another Share Class

If an account no longer meets the balance requirements for a share class, Vanguard may automatically convert the shares in the account to another share class, as appropriate. A decline in the account balance because of market movement may result in such a conversion. Vanguard will notify the investor in writing before any mandatory conversion occurs.

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Redeeming Shares

How to Initiate a Redemption Request

Be sure to check Exchanging Shares, Frequent-Trading Limitations, and Other Rules You Should Know before placing your redemption request.

Online. You may request a redemption of shares or request an exchange through our website or our mobile application if you are registered for online access.

By telephone. You may call Vanguard to request a redemption of shares or an exchange. See Contacting Vanguard.

By mail. You may send a form (available online) to Vanguard to redeem from a fund account or to make an exchange.

How to Receive Redemption Proceeds

By electronic bank transfer. You may have the proceeds of a fund redemption sent directly to a designated bank account. To establish the electronic bank transfer service on an account, you must designate a bank account online, complete a form, or fill out the appropriate section of your account registration form. After the service is set up on your account, you can redeem shares by electronic bank transfer on a regular schedule (Automatic Withdrawal Plan) or upon request. Your redemption request can be initiated online (if you are registered for online access), by telephone, or by mail.

By wire. To receive your proceeds by wire, you may instruct Vanguard to wire your redemption proceeds ($100 minimum) to a previously designated bank account. To establish the wire redemption service, you generally must designate a bank account online, complete a form, or fill out the appropriate section of your account registration form.

Please note that Vanguard charges a $10 wire fee for outgoing wire redemptions. The fee is assessed in addition to, rather than being withheld from, redemption proceeds and is paid directly to the fund in which you invest. For example, if you redeem $100 via a wire, you will receive the full $100, and the $10 fee will be assessed to your fund account through an additional redemption of fund shares. If you redeem your entire fund account, your redemption proceeds will be reduced by the amount of the fee. The wire fee does not apply to accounts held by Flagship and Flagship Select clients; accounts held through intermediaries, including Vanguard Brokerage Services; or accounts held by institutional clients.

By exchange. You may have the proceeds of a Vanguard fund redemption invested directly in shares of another Vanguard fund. You may initiate an exchange online (if you are registered for online access), by telephone, or by mail. See Exchanging Shares.

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By check. If you have not chosen another redemption method, Vanguard will mail you a redemption check, generally payable to all registered account owners, normally within two business days of your trade date, and generally to the address of record.

Trade Date

The trade date for any redemption request received in good order will depend on the day and time Vanguard receives your request and the manner in which you are redeeming. Your redemption will be executed using the NAV as calculated on the trade date. See Share Price.

For redemptions by check, exchange, or wire: If the redemption request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the redemption request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

•Note on timing of wire redemptions from money market funds: For telephone requests received by Vanguard on a business day before 10:45 a.m., Eastern time (2 p.m., Eastern time, for Vanguard Prime Money Market Fund; 12:30 p.m., Eastern time, for Vanguard Federal Money Market Fund), the redemption proceeds generally will leave Vanguard by the close of business the same day. For telephone requests received by Vanguard on a business day after those cut-off times, or on a nonbusiness day, and for all requests other than by telephone, the redemption proceeds generally will leave Vanguard by the close of business on the next business day.

•Note on timing of wire redemptions from all other funds: For requests received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the redemption proceeds generally will leave Vanguard by the close of business on the next business day. For requests received by Vanguard on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the redemption proceeds generally will leave Vanguard by the close of business on the second business day after Vanguard receives the request.

For redemptions by electronic bank transfer: If the redemption request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the redemption request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

If your redemption request is not accurate and complete, it may be rejected. If we are unable to send your redemption proceeds by wire or electronic bank transfer because the receiving institution rejects the transfer, Vanguard will make additional efforts to complete your transaction. If Vanguard is still unable to complete the transaction, we

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may send the proceeds of the redemption to you by check, generally payable to all registered account owners, or use your proceeds to purchase new shares of the fund from which you sold shares for the purpose of the wire or electronic bank transfer transaction. See Other Rules You Should Know—Good Order.

If your redemption request is received in good order, we typically expect that redemption proceeds will be paid by the Fund within one business day of the trade date; however, in certain circumstances, investors may experience a longer settlement period at the time of the transaction. For further information, see "Potentially disruptive redemptions" and "Emergency circumstances."

For further information about redemption transactions, consult our website at vanguard.com or see Contacting Vanguard.

Other Redemption Rules You Should Know

Documentation for certain accounts. Special documentation may be required to redeem from certain types of accounts, such as trust, corporate, nonprofit, or retirement accounts. Please call us before attempting to redeem from these types of accounts.

Potentially disruptive redemptions. Vanguard reserves the right to pay all or part of a redemption in kind—that is, in the form of securities—if we reasonably believe that a cash redemption would negatively affect the fund's operation or performance or that the shareholder may be engaged in market-timing or frequent trading. Under these circumstances, Vanguard also reserves the right to delay payment of the redemption proceeds for up to seven calendar days. By calling us before you attempt to redeem a large dollar amount, you may avoid in-kind or delayed payment of your redemption. Please see Frequent-Trading Limitations for information about Vanguard's policies to limit frequent trading.

Recently purchased shares. Although you can redeem shares at any time, proceeds may not be made available to you until the fund collects payment for your purchase. This may take up to seven calendar days for shares purchased by check or by electronic bank transfer. If you have written a check on a fund with checkwriting privileges, that check may be rejected if your fund account does not have a sufficient available balance.

Address change. If you change your address online or by telephone, there may be up to a 14-day restriction on your ability to request check redemptions online and by telephone. You can request a redemption in writing (using a form available online) at any time. Confirmations of address changes are sent to both the old and new addresses.

Payment to a different person or address. At your request, we can make your redemption check payable, or wire your redemption proceeds, to a different person or

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send it to a different address. However, this generally requires the written consent of all registered account owners and may require additional documentation, such as a signature guarantee or a notarized signature. You may obtain a signature guarantee from some commercial or savings banks, credit unions, trust companies, or member firms of a U.S. stock exchange.

No cancellations. Vanguard will not accept your request to cancel any redemption request once processing has begun. Please be careful when placing a redemption request.

Emergency circumstances. Vanguard funds can postpone payment of redemption proceeds for up to seven calendar days. In addition, Vanguard funds can suspend redemptions and/or postpone payments of redemption proceeds beyond seven calendar days at times when the NYSE is closed or during emergency circumstances, as determined by the SEC.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of one Vanguard fund to simultaneously purchase shares of a different Vanguard fund. You can make exchange requests online (if you are registered for online access), by telephone, or by mail. See Purchasing Shares and Redeeming Shares.

If the NYSE is open for regular trading (generally until 4 p.m., Eastern time, on a business day) at the time an exchange request is received in good order, the trade date generally will be the same day. See Other Rules You Should Know—Good Order for additional information on all transaction requests.

Vanguard will not accept your request to cancel any exchange request once processing has begun. Please be careful when placing an exchange request.

Call Vanguard before attempting to exchange a large dollar amount. By calling us before you attempt to exchange a large dollar amount, you may avoid delayed or rejected transactions.

Please note that Vanguard reserves the right, without notice, to revise or terminate the exchange privilege, limit the amount of any exchange, or reject an exchange, at any time, for any reason. See Frequent-Trading Limitations for additional restrictions on exchanges.

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Frequent-Trading Limitations

Because excessive transactions can disrupt management of a fund and increase the fund's costs for all shareholders, the board of trustees of each Vanguard fund places certain limits on frequent trading in the funds. Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation- Protected Securities Index Fund) limits an investor's purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account. ETF Shares are not subject to these frequent-trading limits.

For Vanguard Retirement Investment Program pooled plans, the limitations apply to exchanges made online or by telephone.

These frequent-trading limitations do not apply to the following:

•Purchases of shares with reinvested dividend or capital gains distributions.

•Transactions through Vanguard's Automatic Investment Plan, Automatic Exchange Service, Direct Deposit Service, Automatic Withdrawal Plan, Required Minimum Distribution Service, and Vanguard Small Business Online®.

•Discretionary transactions through Vanguard Personal Advisor Services®, Vanguard Institutional Advisory Services®, and Vanguard Digital AdvisorTM.

•Redemptions of shares to pay fund or account fees.

•Redemptions of shares to remove excess shareholder contributions to certain types of retirement accounts (including, but not limited to, IRAs and Vanguard Individual 401(k) Plans).

•Transfers and reregistrations of shares within the same fund.

•Purchases of shares by asset transfer or direct rollover.

•Conversions of shares from one share class to another in the same fund.

•Checkwriting redemptions.

•Section 529 college savings plans.

•Certain approved institutional portfolios and asset allocation programs, as well as trades made by funds or trusts managed by Vanguard or its affiliates that invest in other Vanguard funds. (Please note that shareholders of Vanguard's funds of funds are subject to the limitations.)

For participants in employer-sponsored defined contribution plans,* the frequent- trading limitations do not apply to:

•Purchases of shares with participant payroll or employer contributions or loan repayments.

•Purchases of shares with reinvested dividend or capital gains distributions.

•Distributions, loans, and in-service withdrawals from a plan.

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•Redemptions of shares as part of a plan termination or at the direction of the plan.

•Transactions executed through the Vanguard Managed Account Program.

•Redemptions of shares to pay fund or account fees.

•Share or asset transfers or rollovers.

•Reregistrations of shares.

•Conversions of shares from one share class to another in the same fund.

•Exchange requests submitted by written request to Vanguard. (Exchange requests submitted by fax, if otherwise permitted, are subject to the limitations.)

*The following Vanguard fund accounts are subject to the frequent-trading limitations: SEP-IRAs, SIMPLE IRAs, certain Individual 403(b)(7) Custodial Accounts, and Vanguard Individual 401(k) Plans.

Accounts Held by Institutions (Other Than Defined Contribution Plans)

Vanguard will systematically monitor for frequent trading in institutional clients' accounts. If we detect suspicious trading activity, we will investigate and take appropriate action, which may include applying to a client's accounts the 30-day policy previously described, prohibiting a client's purchases of fund shares, and/or revoking the client's exchange privilege.

Accounts Held by Intermediaries

When intermediaries establish accounts in Vanguard funds for the benefit of their clients, we cannot always monitor the trading activity of the individual clients. However, we review trading activity at the intermediary (omnibus) level, and if we detect suspicious activity, we will investigate and take appropriate action. If necessary, Vanguard may prohibit additional purchases of fund shares by an intermediary, including for the benefit of certain of the intermediary's clients. Intermediaries also may monitor their clients' trading activities with respect to Vanguard funds.

For those Vanguard funds that charge purchase and/or redemption fees, intermediaries will be asked to assess these fees on client accounts and remit these fees to the funds. The application of purchase and redemption fees and frequent- trading limitations may vary among intermediaries. There are no assurances that Vanguard will successfully identify all intermediaries or that intermediaries will properly assess purchase and redemption fees or administer frequent-trading limitations. If you invest with Vanguard through an intermediary, please read that firm's materials carefully to learn of any other rules or fees that may apply.

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Other Rules You Should Know

Prospectus and Shareholder Report Mailings

When two or more shareholders have the same last name and address, just one summary prospectus (or prospectus) and/or shareholder report may be sent in an attempt to eliminate the unnecessary expense of duplicate mailings. You may request individual prospectuses and reports by contacting our Client Services Department by telephone or online. See Contacting Vanguard.

Vanguard.com

Registration. If you are a registered user of vanguard.com, you can review your account holdings; buy, sell, or exchange shares of most Vanguard funds; and perform most other transactions through our website. You must register for this service online.

Electronic delivery. Vanguard can deliver your account statements, transaction confirmations, prospectuses, certain tax forms, and shareholder reports electronically. If you are a registered user of vanguard.com, you can consent to the electronic delivery of these documents by logging on and changing your mailing preferences under "Account Maintenance." You can revoke your electronic consent at any time through our website, and we will begin to send paper copies of these documents within 30 days of receiving your revocation.

Telephone Transactions

Automatic. When we set up your account, we will automatically enable you to do business with us by telephone, unless you instruct us otherwise in writing.

Tele-Account®. To obtain fund and account information through Vanguard's automated telephone service, you must first establish a Personal Identification Number (PIN) by calling Tele-Account at 800-662-6273.

Proof of a caller's authority. We reserve the right to refuse a telephone request if the caller is unable to provide the requested information or if we reasonably believe that the caller is not an individual authorized to act on the account. Before we allow a caller to act on an account, we may request the following information:

•Authorization to act on the account (as the account owner or by legal documentation or other means).

•Account registration and address.

•Fund name and account number, if applicable.

•Other information relating to the caller, the account owner, or the account.

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Good Order

We reserve the right to reject any transaction instructions that are not in "good order." Good order generally means that your instructions:

•Are provided by the person(s) authorized in accordance with Vanguard's policies and procedures to access the account and request transactions.

•Include the fund name and account number.

•Include the amount of the transaction (stated in dollars, shares, or percentage). Written instructions also must generally be provided on a Vanguard form and include:

•Signature(s) and date from the authorized person(s).

•Signature guarantees or notarized signatures, if required for the type of transaction. (Call Vanguard for specific requirements.)

•Any supporting documentation that may be required.

Good order requirements may vary among types of accounts and transactions. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Vanguard reserves the right, without notice, to revise the requirements for good order.

Future Trade-Date Requests

Vanguard does not accept requests to hold a purchase, conversion, redemption, or exchange transaction for a future date. All such requests will receive trade dates as previously described in Purchasing Shares, Converting Shares, Redeeming Shares, and Exchanging Shares. Vanguard reserves the right to return future-dated purchase checks.

Accounts With More Than One Owner

If an account has more than one owner or authorized person, Vanguard generally will accept instructions from any one owner or authorized person.

Responsibility for Fraud

You should take precautions to protect yourself from fraud. Keep your account-related information private, and review any account confirmations, statements, or other information that we provide to you as soon as you receive them. Let us know immediately if you discover unauthorized activity or see something on your account that you do not understand or that looks unusual.

Vanguard will not be responsible for losses that result from transactions by a person who we reasonably believe is authorized to act on your account.

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Uncashed Checks

Please cash your distribution or redemption checks promptly. Vanguard will not pay interest on uncashed checks. Vanguard may be required to transfer assets related to uncashed checks to a state under the state's abandoned property law.

Dormant Accounts

If your account has no activity in it for a period of time, Vanguard may be required to transfer it to a state under the state's abandoned property law, subject to potential federal or state withholding taxes.

Unusual Circumstances

If you experience difficulty contacting Vanguard online or by telephone, you can send us your transaction request on a Vanguard form by regular or express mail.

Investing With Vanguard Through Other Firms

You may purchase or sell shares of most Vanguard funds through a financial intermediary, such as a bank, a broker, or an investment advisor. Please consult your financial intermediary to determine which, if any, shares are available through that firm and to learn about other rules that may apply. Your financial intermediary can provide you with account information and any required tax forms. You may be required to pay a commission on purchases of mutual fund shares made through a financial intermediary.

Please see Frequent-Trading Limitations—Accounts Held by Intermediaries for information about the assessment of any purchase or redemption fees and the monitoring of frequent trading for accounts held by intermediaries.

Low-Balance Accounts

The Fund reserves the right to convert an investor's Institutional Shares to another share class, as appropriate, if the fund account balance falls below the account minimum for any reason, including market fluctuation. Any such conversion will be preceded by written notice to the investor.

Right to Change Policies

In addition to the rights expressly stated elsewhere in this prospectus, Vanguard reserves the right, without notice, to (1) alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, conversion, service, or privilege at any time and (2) alter, impose, discontinue, or waive any purchase fee, redemption fee, account service fee, or other fee charged to a shareholder or a group of shareholders. Changes may affect any or all investors. These

39

actions will be taken when, at the sole discretion of Vanguard management, Vanguard believes they are in the best interest of a fund.

Account Restrictions

Vanguard reserves the right to: (1) redeem all or a portion of a fund/account to meet a legal obligation, including tax withholding, tax lien, garnishment order, or other obligation imposed on your account by a court or government agency; (2) redeem shares, close an account, or suspend account privileges, features, or options in the case of threatening conduct or activity; (3) redeem shares, close an account, or suspend account privileges, features, or options if Vanguard believes or suspects that not doing so could result in a suspicious, fraudulent, or illegal transaction; (4) place restrictions on the ability to redeem any or all shares in an account if it is required to do so by a court or government agency; (5) place restrictions on the ability to redeem any or all shares in an account if Vanguard believes that doing so will prevent fraud, financial exploitation or abuse, or to protect vulnerable investors; (6) freeze any account and/or suspend account services if Vanguard has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners; and (7) freeze any account and/or suspend account services upon initial notification to Vanguard of the death of an account owner.

Share Classes

Vanguard reserves the right, without notice, to change the eligibility requirements of its share classes, including the types of clients who are eligible to purchase each share class.

Fund and Account Updates

Confirmation Statements

We will send (or provide through our website, whichever you prefer) a confirmation of your trade date and the amount of your transaction when you buy, sell, exchange, or convert shares. However, we will not send confirmations reflecting only checkwriting redemptions or the reinvestment of dividend or capital gains distributions. For any month in which you had a checkwriting redemption, a Checkwriting Activity Statement will be sent to you itemizing the checkwriting redemptions for that month. Promptly review each confirmation statement that we provide to you. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on a confirmation statement, or Vanguard will consider the transaction properly processed.

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Portfolio Summaries

We will send (or provide through our website, whichever you prefer) quarterly portfolio summaries to help you keep track of your accounts throughout the year. Each summary shows the market value of your account at the close of the statement period, as well as all distributions, purchases, redemptions, exchanges, transfers, and conversions for the current calendar quarter (or month). Promptly review each summary that we provide to you. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on the summary, or Vanguard will consider the transaction properly processed.

Tax Information Statements

For most accounts, Vanguard (or your intermediary) is required to provide annual tax forms to assist you in preparing your income tax returns. These forms are generally available for each calendar year early in the following year. Registered users of vanguard.com can also view certain forms through our website. Vanguard (or your intermediary) may also provide you with additional tax-related documentation. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Annual and Semiannual Reports

We will send (or provide through our website, whichever you prefer) reports about Vanguard Total International Bond Index Fund twice a year, in June and December. These reports include overviews of the financial markets and provide the following specific Fund information:

•Performance assessments and comparisons with industry benchmarks.

•Financial statements with listings of Fund holdings.

Portfolio Holdings

Please consult the Fund's Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund's portfolio holdings.

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Employer-Sponsored Plans

Your plan administrator or your employee benefits office can provide you with detailed information on how to participate in your plan and how to elect the Fund as an investment option.

•If you have any questions about the Fund or Vanguard, including those about the Fund's investment objective, strategies, or risks, contact Vanguard Participant Services toll-free at 800-523-1188 or visit our website at vanguard.com.

•If you have questions about your account, contact your plan administrator or the organization that provides recordkeeping services for your plan.

•Be sure to carefully read each topic that pertains to your transactions with Vanguard.

Vanguard reserves the right to change its policies without notice to shareholders.

Transactions

Processing times for your transaction requests may differ among recordkeepers or among transaction and funding types. Your plan's recordkeeper (which may also be Vanguard) will determine the necessary processing time frames for your transaction requests prior to submission to the Fund. Consult your recordkeeper or plan administrator for more information.

If Vanguard is serving as your plan recordkeeper and if your transaction involves one or more investments with an early cut-off time for processing or another trading restriction, your entire transaction will be subject to the restriction when the trade date for your transaction is determined.

Contacting Vanguard

Web

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CFA® is a registered trademark owned by CFA Institute.

BLOOMBERG is a trademark and service mark of Bloomberg Finance L.P. BARCLAYS is a trademark and service mark of Barclays Bank Plc, used under license. Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL) (collectively, Bloomberg), or Bloomberg's licensors, own all proprietary rights in the Bloomberg Barclays Global Aggregate ex-USD Float Adjusted RIC Capped Index (USD Hedged) (the Index or Bloomberg Barclays Index).

Neither Barclays Bank Plc, Barclays Capital Inc., or any affiliate (collectively Barclays) or Bloomberg is the issuer or producer of the Total International Bond Index Fund and neither Bloomberg nor Barclays has any responsibilities, obligations or duties to investors in the Total International Bond Index Fund. The Index is licensed for use by The Vanguard Group, Inc. (Vanguard) as the sponsor of the Total International Bond Index Fund. Bloomberg and Barclays' only relationship with Vanguard in respect to the Index is the licensing of the Index, which is determined, composed and calculated by BISL, or any successor thereto, without regard to the Issuer or the Total International Bond Index Fund or the owners of the Total International Bond Index Fund.

Additionally, Vanguard may for itself execute transaction(s) with Barclays in or relating to the Index in connection with the Total International Bond Index Fund. Investors acquire the Total International Bond Index Fund from Vanguard and investors neither acquire any interest in the Index nor enter into any relationship of any kind whatsoever with Bloomberg or Barclays upon making an investment in the Total International Bond Index Fund. The Total International Bond Index Fund is not sponsored, endorsed, sold or promoted by Bloomberg or Barclays. Neither Bloomberg nor Barclays makes any representation or warranty, express or implied regarding the advisability of investing in the Total International Bond Index Fund or the advisability of investing in securities generally or the ability of the Index to track corresponding or relative market performance. Neither Bloomberg nor Barclays has passed on the legality or suitability of the Total International Bond Index Fund with respect to any person or entity. Neither Bloomberg nor Barclays is responsible for and has not participated in the determination of the timing of, prices at, or quantities of the Total International Bond Index Fund to be issued. Neither Bloomberg nor Barclays has any obligation to take the needs of the Issuer or the owners of the Total International Bond Index Fund or any other third party into consideration in determining, composing or calculating the Index. Neither Bloomberg nor Barclays has any obligation or liability in connection with administration, marketing or trading of the Total International Bond Index Fund.

The licensing agreement between Bloomberg and Barclays is solely for the benefit of Bloomberg and Barclays and not for the benefit of the owners of the Total International Bond Index Fund, investors or other third parties. In addition, the licensing agreement between Vanguard and Bloomberg is solely for the benefit of Vanguard and Bloomberg and not for the benefit of the owners of the Total International Bond Index Fund, investors or other third parties.

NEITHER BLOOMBERG NOR BARCLAYS SHALL HAVE ANY LIABILITY TO THE ISSUER, INVESTORS OR TO OTHER THIRD PARTIES FOR THE QUALITY, ACCURACY AND/OR COMPLETENESS OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR FOR INTERRUPTIONS IN THE DELIVERY OF THE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY THE ISSUER, THE INVESTORS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY EXPRESS OR IMPLIED WARRANTIES, AND EACH HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. BLOOMBERG RESERVES THE RIGHT TO CHANGE THE METHODS OF CALCULATION OR PUBLICATION, OR TO CEASE THE CALCULATION OR PUBLICATION OF THE BLOOMBERG BARCLAYS INDEX, AND NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY MISCALCULATION OF OR ANY INCORRECT, DELAYED OR INTERRUPTED PUBLICATION WITH RESPECT TO THE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY DAMAGES, INCLUDING, WITHOUT LIMITATION, ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY LOST PROFITS AND EVEN IF ADVISED OF THE POSSIBILITY OF SUCH, RESULTING FROM THE USE OF A BLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR WITH RESPECT TO THE TOTAL INTERNATIONAL BOND INDEX FUND.

None of the information supplied by Bloomberg or Barclays and used in this publication may be reproduced in any manner without the prior written permission of both Bloomberg and Barclays Capital, the investment banking division of Barclays Bank Plc. Barclays Bank Plc is registered in England No. 1026167. Registered office 1 Churchill Place London E14 5HP.

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Glossary of Investment Terms

Average Maturity. The average length of time until bonds held by a fund reach maturity and are repaid. In general, the longer the average maturity, the more a fund's share price fluctuates in response to changes in market interest rates. In calculating average maturity, a fund uses a bond's maturity or, if applicable, an earlier date on which the advisor believes it is likely that a maturity-shortening device (such as a call, a put, a refunding, a prepayment, or a redemption provision or an adjustable coupon rate) will cause the bond to be repaid.

Bond. A debt security (IOU) issued by a corporation, a government, or a government agency in exchange for the money the bondholder lends it. In most instances, the issuer agrees to pay back the loan by a specific date and generally to make regular interest payments until that date.

Capital Gains Distributions. Payments to mutual fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Coupon Rate. The interest rate paid by the issuer of a debt security until its maturity. It is expressed as an annual percentage of the face value of the security.

Dividend Distributions. Payments to mutual fund shareholders of income from interest or dividends generated by a fund's investments.

Expense Ratio. A fund's total annual operating expenses expressed as a percentage of the fund's average net assets. The expense ratio includes management and administrative expenses, but it does not include the transaction costs of buying and selling portfolio securities.

Face Value. The amount to be paid at a bond's maturity; also known as the par value or principal.

Fixed Income Security. An investment, such as a bond, representing a debt that must be repaid by a specified date, and on which the borrower must pay a fixed, variable, or floating rate of interest.

Float-Adjusted Index. An index that weights its constituent securities based on the value of the constituent securities that are available for public trading, rather than the value of all constituent securities. Some portion of an issuer's securities may be unavailable for public trading because, for example, those securities are owned by company insiders on a restricted basis or by a government agency. By excluding unavailable securities, float-adjusted indexes can produce a more accurate picture of the returns actually experienced by investors in the measured market.

Inception Date. The date on which the assets of a fund (or one of its share classes) are first invested in accordance with the fund's investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.

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Indexing. A low-cost investment strategy in which a mutual fund attempts to track— rather than outperform—a specified market benchmark, or "index."

Investment-Grade Bond. A debt security whose credit quality is considered by independent bond rating agencies, or through independent analysis conducted by a fund's advisor, to be sufficient to ensure timely payment of principal and interest under current economic circumstances. Debt securities rated in one of the four highest rating categories are considered investment-grade. Other debt securities may be considered by an advisor to be investment-grade.

Joint Committed Credit Facility. The Fund participates, along with other funds managed by Vanguard, in a committed credit facility provided by a syndicate of lenders pursuant to a credit agreement that may be renewed annually; each Vanguard fund is individually liable for its borrowings, if any, under the credit facility. The amount and terms of the committed credit facility are subject to approval by the Fund's board of trustees and renegotiation with the lender syndicate on an annual basis.

Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.

New York Stock Exchange (NYSE). A stock exchange based in New York City that is open for regular trading on business days, Monday through Friday, from 9:30 a.m. to 4 p.m., Eastern time.

Principal. The face value of a debt instrument or the amount of money put into an investment.

Securities. Stocks, bonds, money market instruments, and other investments.

Total Return. A percentage change, over a specified time period, in a mutual fund's net asset value, assuming the reinvestment of all distributions of dividends and capital gains.

Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund's volatility, the wider the fluctuations in its returns.

Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment's price.

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Institutional Division

P.O. Box 2900

Valley Forge, PA 19482-2900

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