Stocks ended Tuesday's shortened session lower as profit warnings from Internet security firms such as Internet Security Systems Inc. dented yet another sector of the beleaguered market.
Blue chips took a hit after top chemical maker DuPont said it will miss earnings forecasts because of the struggling economy.
Some 1,009 companies now have hinted at their quarterly results, and 688 have warned they will miss expectations, according to research firm Thomson Financial.
The technology-laced Nasdaq Composite Index fell 10.51 points, or 0.49 percent, to 2,138.21 Tuesday.
The Dow Jones industrial average was off 22.41 points, or 0.21 percent, at 10,571.31, while the Standard & Poor's 500 Index lost 2.67 points, or 0.22 percent, at 1,234.04.