Stocks gave up their morning gains after Federal Reserve Chairman Ben Bernanke offered no specific plans to stimulate the economy in an afternoon speech.
Economic signs were mixed. First-time applications for unemployment rose more than analysts were predicting, a sign that the job market continues to be weak. However, US exports rose to a record level, a signal that some economists say could lead to economic growth.
The Dow Jones industrial average fell 119.05, or 1 percent, to 11,295.81.
The Standard & Poor's 500 index dropped 12.72, or 1.1 percent, to 1,185.90.
The Nasdaq composite shed 19.80, or 0.8 percent, to 2,529.14.
For the week:
The Dow is up 55.55, or 0.5 percent.
The S&P 500 is up 11.93, or 1 percent.
The Nasdaq is up 48.81, or 2 percent.
For the year to date:
The Dow is down 281.70, or 2.4 percent.
The S&P 500 is down 71.74, or 5.7 percent.
The Nasdaq is down 123.73, or 4.7 percent.