Wall Street extends rally 4th day, S&P up on year

NEW YORK (Reuters) - Wall Street stocks rose on Friday as the S&P 500 rallied for a fourth straight day and turned positive for the year after a run of better-than-expected economic data. The S&P 500 has gained nearly 5 percent over the last four days and is slightly higher for the year. Investors cited recent improvement in U.S. economic data and seasonal factors behind the move, but many remained cautious about the 2012 outlook. The U.S. Congress approved a two-month extension of a payroll tax cut for 160 million workers that otherwise would have expired on December 31. ...