Stocks rose at the open on Wednesday, following two days of sharp losses, with developments in Greece and a U.S. monetary policy meeting on investors' minds.

The Dow Jones industrial average was up 153.41 points, or 1.32 percent, at 11,811.37. The Standard & Poor's 500 Index was up 17.99 points, or 1.48 percent, at 1,236.27. The Nasdaq Composite Index was up 33.01 points, or 1.27 percent, at 2,639.97.

(Reporting by Angela Moon; editing by Jeffrey Benkoe)