This story was updated at 4:10 p.m. EST.

U.S. stocks closed mixed on Wednesday as investors digested Federal Reserve Chair Janet Yellen’s policy hearing to Congress. During her remarks, Yellen cited global uncertainties as potential risk to the U.S. economy but played down chances of a significant shift in monetary policy toward gradual interest rate hikes that began in December. The Dow seesawed from a 200-point gain in the morning to nearly 100 points down by the closing bell. The Nasdaq closed up on a rally in tech stocks.

“Financial conditions in the United States have recently become less supportive of growth,” Yellen said in prepared remarks released ahead of the 10 a.m. semiannual monetary policy address to the House of Representatives. “Still, ongoing employment gains and faster wage growth should support the growth of real incomes and therefore consumer spending, and global economic growth should pick up over time, supported by highly accommodative monetary policies abroad . ”

The Dow Jones Industrial Average (INDEXDJX:.DJI) closed down 99.85 points or 0.62 percent to 15,914.53. The broader Standard & Poor's 500 index (INDEXSP:.INX) was flat, down just 0.38 points, or 0.02 percent to 1,851.85. The Nasdaq composite (INDEXNASDAQ:.IXIC) gained 14.83 points, or 0.35 percent to 4,283.59.

Eight of the 10 S&P 500 sectors were down by the bell Wednesday with just healthcare and tech stocks in positive territory. Leading Dow gains were Nike Inc. (NYSE:NKE) and Visa Inc. (NYSE:V). Leading decliners: Walt Disney Co. (NYSE:DIS) and International Business Machines Corp. (NYSE:IBM).

Treasury Yield Drops

The yield on the benchmark U.S. 10-year Treasury yield fell to 1.70 after touching 1.76 at around 10:30 a.m. The bond yield typically rises when investors are more confident about the markets and falls when concerns flare. Gold, another so-called safe-harbor investment, shed 0.12 percent to $1,197.20 per troy ounce, around its highest level since last summer. Gold prices tend to fall as confidence in the markets rises.

Oil Prices

Oil prices were mixed Wednesday after the previous session’s rout.

U.S. West Texas Intermediate lost 1.04 percent to $27.65 per barrel for March delivery on the New York Mercantile Exchange. Brent crude, the other major global benchmark, rose 2.51 percent to $31.08 for April delivery on the London ICE Futures Exchange.

Global Markets

Hong Kong and other Asian markets are closed until Thursday for the Lunar New Year holiday. China’s mainland markets are closed for the week. Japan’s Nikkei dropped 2.3 percent.

In Europe, the broad Stoxx Europe 600 index closed up 1.9 percent Wednesday. The Paris-based CAC 40 advanced 1.6 percent, while London’s FTSE was up 0.7 percent. Frankfurt’s DAX rose 1.6 percent.

Market Movers

European bank stocks rallied Wednesday as investors bought on dips. Financial stocks faced a big selloff earlier this week over worries about slowing global growth and rock-bottom interest rates that dig into profits earned from lending.

SolarCity Corp. (NASDAQ:SCTY) shares plunged 27 percent Wednesday morning after reporting lower-than-expected solar system installations and issued a downbeat forecast for the current quarter.

Time Warner Inc. (NYSE:TWX) shares dropped 4.7 percent after the company reported lower-than-expected fourth quarter revenue. The company gave an upbeat outlook for its 2016 earnings.

Panera Bread Co. (NASDAQ:PNRA) stock jumped nearly 5 percent after reporting higher-than-expected profit. Revenue failed to beat estimates but the company reported better performance in the current quarter.

Tesla Motors Inc. (NASDAQ:TSLA) shares were up 2.6 percent Wednesday morning after touching a 52-week low earlier in the week. The Palo Alto electric carmaker reports its fourth quarter and full-year 2015 results after markets close Wednesday.