U.S. stocks pared gains but were still at 2009 highs on Monday after Federal Reserve Chairman Ben Bernanke said the U.S. central bank is attentive to changes in the dollar and the Fed's mandate will help ensure the greenback remains strong.

Weakness in the U.S. currency earlier helped lift commodity and stock prices.

The Dow Jones industrial average <.DJI> gained 107.24 points, or 1.04 percent, to 10,377.71. The Standard & Poor's 500 Index <.SPX> added 13.81 points, or 1.26 percent, to 1,107.29. The Nasdaq Composite Index <.IXIC> rose 26.75 points, or 1.23 percent, to 2,194.63.

(Editing by Kenneth Barry)

Ben Bernanke