Stocks fell for a second day on Thursday as labor market data showed more signs of weakness while a warning from Qualcomm and poor results from Stanley Black & Decker discouraged investors.

The Dow Jones industrial average slid 68.73 points, or 0.53 percent, to end unofficially at 12,964.02. The Standard & Poor's 500 Index fell 8.22 points, or 0.59 percent, to finish unofficially at 1,376.92. The Nasdaq Composite Index dropped 23.89 points, or 0.79 percent, to close unofficially at 3,007.56.

(Reporting by Angela Moon; Editing by Jan Paschal)