The Federal Reserve's latest signals on interest rates gave U.S. stocks a lift for much of Wednesday, but the rally didn't last.
A sell-off in the final minutes of trading knocked the Dow Jones industrial average and the Standard & Poor's 500 index slightly into the red. The slide extended a three-day losing streak for the two indexes. The Nasdaq composite carved out a slight gain.
Materials and energy stocks were among the biggest decliners as U.S. crude oil prices declined again.
Investors were mostly focused on Fed Chairwoman Janet L. Yellen's remarks to Congress.
The Dow fell 99.64 points, or 0.6%, to 15,914.74. The S&P 500 index slipped 0.35 point, or 0.02%, to 1,851.86. The Nasdaq composite index rose 14.83 points, or 0.4%, to 4,283.59.
Investors appeared to be in a buying mood early in the day in anticipation of Yellen's testimony. That sent stocks higher early on and sustained them until the last-minute slide as oil prices closed lower.
Benchmark U.S. crude fell 49 cents, or 1.8%, to close at $27.45 a barrel in New York. Brent crude, a benchmark for international oils, climbed 52 cents, or 1.7%, to close at $30.84 a barrel in London.
All told, eight of the 10 sectors in the S&P 500 index declined, with materials and energy stocks posting the biggest drops. Healthcare and technology stocks bucked the downward trend.
Akamai Technologies, which provides online cloud services, notched the biggest increase in the S&P 500 index, surging 21.2%. Assurant, which provides insurance products and related services, fell the most, losing 13.4%.
Several big media companies slumped.
Walt Disney dropped 3.8% a day after it reported that its ESPN network had hit a soft patch. The stock was the biggest decliner in the Dow. Time Warner was down 5% after its revenue fell short of forecasts.
Precious metals prices closed lower. Gold fell $4, or 0.3%, to $1,194.60 an ounce. Silver slid 17 cents, or 1.1%, to $15.28 an ounce. Copper, an industrial metal that often rises and falls along with investors' optimism about the global economy, fell 1 cent, or 0.6%, to $2.03 a pound.
Bond prices rose. The yield on the 10-year Treasury slipped to 1.67% from 1.73% late Tuesday.
The dollar fell to 113.68 yen from 115.01 yen. The euro rose to $1.1277 from $1.1287.
Wholesale gasoline rose 4 cents, or 4.9%, to 94 cents a gallon. Home heating oil was flat at 97 cents a gallon. Natural gas fell 5 cents, or 2.5%, to $2.05 per 1,000 cubic feet.
Markets were closed in China, Taiwan, Hong Kong and South Korea for Lunar New Year holidays. Hong Kong and Korea are to reopen Thursday, and China and Taiwan resume trading Monday.