By Alexandra Scaggs And Saumya Vaishampayan 

U.S. stocks were mixed Wednesday after two consecutive days of gains for the Dow industrials and the S&P 500.

Investors are looking ahead to the release of minutes from the Federal Reserve's latest monetary-policy meeting at 2 p.m. Eastern.

The Dow Jones Industrial Average tacked on 15 points, or 0.1%, to 16935. The S&P 500 index was little changed, gaining less than 0.1% to 1982, and the Nasdaq Composite Index shed five points, or 0.1%, to 4522.

Stocks rose Tuesday, which marked the third-slowest full trading day of the year. The Dow gained 0.5% to 16919.59 and the S&P 500 rose 0.5% to 1981.60.

Central bankers are in the spotlight this week, between the Fed meeting minutes and a closely watched annual gathering of central bankers in Jackson Hole, Wyo., where Fed Chairwoman Janet Yellen and European Central Bank President Mario Draghi are scheduled to speak later this week.

Investors will be eyeing both events to determine the outlook for central-bank policy. Many say that persistently low interest rates have supported stock-market gains this year by keeping bond yields low and pushing investors to search for yield in riskier parts of the market.

As a result, "you're getting a lot of people crowded into pretty small spaces where they think there's opportunity," said Ralph Segall, chief investment officer of Segall Bryant & Hamill, which manages $9.5 billion. "This is a time you're worried about making sure you don't get run over."

Mr. Segall said that U.S. stocks could be vulnerable to a sharp selloff if the broad hunt for yield changes course. As a result, his team has been buying stocks that trade at relatively low valuations, in hopes those stocks will hold up if broader stock benchmarks take a dive.

Still, if Wednesday's minutes indicate that officials are willing to keep short-term interest rates low, stocks could push higher, said Michael Arone, chief investment strategist for State Street Global Advisors' U.S. Intermediary Business.

"The [economic data] that we're seeing continue to indicate that the economy is improving, particularly areas where we had structural problems like housing and labor, yet inflation remains fairly benign," he said. "That is a very positive environment for U.S. stocks."

Strategists say that improving economic data and corporate earnings are other factors that have helped push the stock market higher this year. The Dow and the S&P 500 recovered from a pullback in January and early February to advance to a series of fresh records.

Stocks have recently staged a recovery from a mid-July pullback, which was sparked by a bout of geopolitical fears and concerns about the end of the Fed's loose monetary policy. As of Tuesday's close, the Dow was off 1.3% from its July 16 record and the S&P was just 0.3% below its July 24 record.

European stocks pulled back, with the Stoxx Europe 600 Index down 0.4%.

Treasury prices fell as well, pushing the yield on the 10-year Treasury note up to 2.418%, according to FactSet.

In corporate news, Lowe's Cos. Inc. reported better-than-expected results in the second quarter. But shares fell 0.4% as the company lowered its sales outlook for the full year.

PetSmart Inc. said it would explore strategic alternatives, including a possible sale. The company said it would implement a cost-reduction program. Shares rose 0.2%.

In commodity markets, crude-oil futures rose 0.5% to $93.35 a barrel. Gold futures slipped 0.2% to $1,294.70 an ounce.

Write to Alexandra Scaggs at alexandra.scaggs@wsj.com