ECB President Mario Draghi sought to reassure investors Friday

"I think the markets overreacted...emotions took over," said Kate Warne, investment strategist at Edward Jones, referring to Thursday's selloff.

The yield on the benchmark 10-year Treasury note fell to 2.275%, from 2.328% Thursday .

The euro fell 0.5% against the U.S. dollar to $1.0885 Friday, after rising 3.1% Thursday. The dollar rose 0.4% against Japan's yen to Yen123.1160.

The Stoxx Europe 600 fell 0.4% Friday after falling 3.1% Thursday--its biggest daily loss since August.

ECB President Mario Draghi sought to reassure investors Friday. The central bank would "no doubt" step up stimulus measures if needed, Mr. Draghi said at an Economic Club of New York event.

"I think [Draghi] is putting in a little bit of work to explain more clearly what the ECB was doing yesterday," said Shaun Osborne, chief FX strategist at Scotiabank. "It's very possible that they are back at it next year."

Gold futures rose 2.1% to $1,084.50. If the Fed raises rates slowly, as investors expect, it could be good news for gold prices, which struggles to compete with yield-bearing investments when borrowing costs rise.

In Asia on Friday, Japan's Nikkei Stock Average fell 2.2%, Australia's S&P/ASX 200 fell 1.5%, and the Shanghai Composite Index fell 1.7%.

December 04, 2015 20:20 ET (01:20 GMT)