US stocks flat after gains on retail sales

US stocks gave up early gains helped by a better-than-expected reading on retail sales to close flat Tuesday, with the Dow held up by a strong performance from Home Depot. But a poor report from Groupon pulled it and other social media shares sharply lower, with Groupon ending down 26.8 percent. The blue-chip Dow Jones Industrial Average ended up 2.71 points (0.02 percent) to 13,172.14, after having surged around 53 points in early trade. The broader S&P 500-stock index slipped a bare 0.19 (0.01 percent) to 1,403.92. But Groupon's plunge helped pull the tech-rich Nasdaq lower, the index giving up 5.54 points (0.18 percent) to 3,016.98.