Stocks finished narrowly mixed on light volume Wednesday with little news to push them one way or the other. The Nasdaq and S&P 500 were practically flat, while the Dow Jones industrial average gained 0.1%. In the stock market today, Aruba Networks (SWHC) was a big gainer on better-than-expected earnings, and gun maker Smith & Wesson (SWHC) was a big loser as it missed on earnings, reporting that sales of rifles and shotguns were flagging.