Traders were discouraged Friday by another slump in the price of oil and more signs of weakness in China.
The Dow dropped 315 points, or 1.8 per cent, to 17,280. The Dow had its first losing week since October.
The Standard & Poor's 500 fell 33 points, or 1.6 per cent, to 2,002. The Nasdaq slid 54 points, or 1.2 per cent, to 4,653.
Oil prices sank again after the International Energy Agency said global demand will grow less than previously forecast next year.
Crude tumbled $2.14, or 3.6 per cent, to $57.81 a barrel. It's down 47 per cent since June.
Bond prices rose. The yield on the 10-year Treasury note fell to 2.09 per cent.