Stocks edged lower at the open on Friday as a pullback in commodity prices weighed on natural resource shares after the U.S. dollar rebounded.

The dollar rose broadly after Federal Reserve Chairman Ben Bernanke said that monetary policy might have to be tightened as a recovery takes hold.

The Dow Jones industrial average <.DJI> fell 6.50 points, or 0.07 percent, to 9,780.37. The Standard & Poor's 500 Index <.SPX> lost 1.40 points, or 0.13 percent, to 1,064.08. The Nasdaq Composite Index <.IXIC> dropped 3.30 points, or 0.16 percent, to 2,120.63.

(Editing by Jeffrey Benkoe)