Stocks extended losses on Wednesday after data showing weaker-than-expected existing-home sales added to concerns about the U.S. economy.

The Dow Jones industrial average was down 50.81 points, or 0.37 percent, at 13,625.42. The Standard & Poor's 500 Index was down 9.20 points, or 0.61 percent, at 1,510.39. The Nasdaq Composite Index was down 28.63 points, or 1.02 percent, at 2,770.63.