Wall St ends flat

U.S. stocks closed flat in volatile trading as Fed Chairman Ben Bernanke's negative comments on looming fiscal cliff dampened gains.
Dow Jones Industrial Average slipped 7.45 points, or 0.06 per cent to end at 12,788.51.
S&P 500 gained 0.92 points, or 0.07 per cent at 1,387.81
Among key S&P sectors, technology and energy shares slipped, while health care gained.
Nasdaq composite added 0.61 points, or 0.02 per cent at 2,916.68.