The Dow Jones industrial average had its worst one-day drop since February, erasing its gain for the year, as traders worried about weak corporate earnings and the looming end of economic stimulus from the Federal Reserve. The slide interrupted a prolonged advance in the market which brought the Standard & Poor's 500 index to its latest record high close just one week ago.
The Dow Jones industrial average slipped 317.06 points, or 1.9 percent, to close at 16,563.30.
The Standard & Poor's 500 index ended with a loss of 39.40 points, or 2 percent, at 1,930.67.
The Nasdaq composite fell 93.13 points, or 2.1 percent, to 4,369.77.
For the week:
The Dow is down 397.27 points, or 2.3 percent.
The S&P 500 is down 47.67 points, or 2.4 percent.
The Nasdaq is down 79.79 points, 1.8 percent.
For the year:
The Dow is down 13.36 points, or 0.1 percent.
The S&P 500 index is up 82.31 points, or 4.5 percent.
The Nasdaq is up 193.18 points, or 4.6 percent