NEW YORK, May 22 (Reuters) - U.S. stocks rose slightly at the open, ahead of highly anticipated testimony in Congress by Federal Reserve Chairman Ben Bernanke on the economy and monetary policy.
The Dow Jones industrial average gained 18.20 points, or 0.12 percent, to 15,405.78. The Standard & Poor's 500 Index added 1.97 points, or 0.12 percent, to 1,671.13. The Nasdaq Composite Index rose 1.63 points, or 0.05 percent, to 3,503.75.