Stocks opened sharply lower on Wednesday after General Motors Corp posted its biggest ever quarterly loss, oil moved closer to $100 and the dollar tumbled, casting doubt on the U.S. economic outlook and prospects for corporate profits.

The Dow Jones industrial average was down 128.03 points, or 0.94 percent, at 13,532.91. The Standard & Poor's 500 Index was down 13.40 points, or 0.88 percent, at 1,506.87. The Nasdaq Composite Index was down 25.54 points, or 0.90 percent, at 2,799.64.