Five minutes into trade, the Dow Jones Industrial Average was up 13.93 points (0.11 percent) to 12,463.38. The broad-based S&P 500 was up 3.53 points (0.27 percent) to 1,296.01, while the tech-rich Nasdaq Composite rose 6.03 points (0.22 percent) to 2,716.79. Weekly jobless claims, an indicator of the pace of layoffs, rose to 399,000 after steadily falling for several weeks, raising the possibility that the recent improvement in the jobs sector may have been temporary. Meanwhile retail sales in December were flat from the month before, confirming worries that the holiday shopping season was clouded by reticent shoppers and heavy discounting.