Remarks by Federal Reserve Chairman Ben Bernanke that dimmed hopes for a third round of bond-buying pushed stocks lower Thursday.
In a second day of testimony, Bernanke told lawmakers the Fed expects the economy to improve. He said the central bank would only step in with more economic stimulus if there is a significant downturn in the economy.
"We're not prepared at this point to take further action," Bernanke said.
Stocks turned immediately lower after the remarks and fell for much of the day.
Bernanke was clarifying statements he made Wednesday that left the door open to new economic stimulus measures. Investors took his earlier remarks to mean that the Fed chairman had all but guaranteed new action to stimulate the economy, said Jeff Cleveland, senior economist at money manager Payden & Rygel.
"They realize that's not the case now," Cleveland said.
The Standard & Poor's 500 index fell 8.85 points, or 0.7 percent, to close at 1,308.87. The Dow Jones industrial average fell 54.49, or 0.4 percent, to 12,437.12. The Nasdaq composite fell 34.25, or 1.2 percent, to 2,762.67.
It was the fourth day of losses on the stock market out of the last five. Worries that Italy could be the next European country to get caught up in the region's debt problems have kept investors on edge this week.
Google Inc. rose 12 percent in after-hours trading after the company reported earnings that soared past analyst expectations. The results calmed investors who were concerned that a leadership shake-up would hurt the company.
JPMorgan Chase & Co. rose 1.8 percent after the bank reported that higher investment banking fees raised its net income above analysts' expectations.
ConocoPhillips rose 1.6 percent after the country's third-largest oil company said it would split in two. One company will be an oil producer, and the other a refinery. Investors preferred two simple businesses to one complicated one.
Stocks started higher after applications for unemployment benefits fell to a three-month low last week, a sign that companies are laying off fewer workers. At 405,000, the figure is still above the 375,000 that signals healthy job growth.
In a separate report, the government also said an increase in car sales and a drop in gas prices pushed up retail sales slightly in June.
Stocks were also held back by a stalemate in Washington over raising the country's borrowing limit. Late Wednesday Moody's threatened to lower the U.S. credit rating below the highest grade of triple-A, citing the risk that the government might fail to make its debt payments if an agreement isn't reached by an Aug. 2 deadline.
In Europe, a threat resurfaced that Italy's government could lose control of the country's debt crisis. Yields on Italy's debt jumped to their highest level since the introduction of the euro following a bond sale. A debt default for an economy as large as Italy's would hurt lending across the globe.
Marriott International Inc. fell 6.6 percent after the hotel chain said it would earn less in the full year than previously expected.
YUM Brands Inc. rose 1.4 percent after the owner of the Pizza Hut, Taco Bell and KFC fast-food chains said its earnings rose on strong international sales.
About four stocks fell for every one that rose on the New York Stock Exchange. Volume was light at 3.8 billion.
AP Economics Writer Martin Crutsinger contributed to this story.