Bill Gross said the three-decade bull market in bonds ended last week when the 10-year Treasury yield hit 1.67%, but the manager of the world's largest bond fund stressed that a bear market in bonds won't start until economic growth and inflation pick up.

Mr. Gross, founder and co-chief investment officer of Pacific Investment Management Co. and manager of the Pimco Total Return fund, made the comments Friday on his Twitter account and in a subsequent interview with The Wall Street Journal.

The 10-year Treasury note declined in price Friday, yielding 1.88%.

Write to Min Zeng at min.zeng@dowjones.com

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