By Katy Burne 

Investors yanked $2.75 billion from funds dedicated to low-rated corporate debt, in the latest sign of nerves about economic headwinds and turbulence in global bond markets.

The outflow was the largest weekly drawdown since $3.1 billion flowed out of the funds in the week ended Dec. 17, said fund tracker Lipper.

Exchange-traded funds bore a significant brunt of the outflows. Some $585 million came out of State Street Corp.'s SPDR Barclays High Yield Bond ETF, bearing the ticker symbol JNK, Lipper said.

A full $1.6 billion came out of the BlackRock Inc.-owned iShares iBoxx $ High Yield Corporate Bond ETF, which uses the ticker HYG, Lipper said.

"The rout of European bonds caught investors by surprise," said Jeff Tjornehoj, head of Lipper Americas research. Adding to the unease, he said, was a disappointing jobs report this week, showing private-sector payrolls expanded at a mediocre pace. "There seems to be a few bumps in the road."

Junk-bond prices had been on a tear, leading some investors to question how long the rally could last. Janet Yellen, head of the U.S. Federal Reserve, was the latest voice to draw attention to stock and junk-bond markets overheating in comments earlier this week.

Now, investors appear to be taking a breather, worried that market jitters may put a pause in their run-up. Total returns on U.S. junk bonds, which account for price appreciation and interest payments, are down 0.06% for the month to date, according to Barclays PLC, but are up 3.69% for the year.

Write to Katy Burne at katy.burne@wsj.com

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