Wall Street extends year-end rally, S&P up on year

NEW YORK (Reuters) - Wall Street extended a year-end rally on Friday as the S&P 500 rose for a fourth day and turned positive for the year after a recent run of better-than-expected economic data. The S&P 500 has rallied 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 are still cautious about the 2012 outlook. The U.S. Congress approved a two-month extension of a payroll tax cut for 160 million American workers that otherwise would have expired on December 31. ...