NEW YORK (AP) â¿¿ U.S. stock futures are holding onto early gains following a slight uptick in weekly unemployment claims and a marginally brighter outlook on economic activity in the last quarter of 2012. Dow Jones industrial futures are up 18 points to 14,463 on the last trading day of the quarter. The broader S&P 500 futures are up 1 point to 1,558. Nasdaq futures are up 6 points to 2,807. The number of Americans seeking unemployment benefits jumped by 16,000 last week, the second straight weekly increase. In addition, a government report says the U.S. economy grew at a slightly faster but still anemic rate of 0.4 percent for the October-December quarter at the end of last year. That was better than the previous estimate of 0.1 percent growth.