pU.S. stocks edged lower at the open on Wednesday (January 30) following an unexpected contraction in fourth-quarter economic activity, but losses were curbed by gains in Internet retailer Amazon.com.pbr pThe Dow Jones industrial average dropped 11.13 points, or 0.08 percent, to 13,943.29. The Standard & Poor's 500 Index shed 1.34 points, or 0.09 percent, to 1,506.50. The Nasdaq Composite Index gained 1.48 points, or 0.05 percent, to 3,155.14.pbr pU.S. gross domestic product fell 0.1 percent, far below expectations for growth of 1.1 percent. However, a read on private sector employment topped forecasts, with the ADP National Employment report showing 192,000 jobs added in January, higher than the 165,000 expectation.