US stocks rose on Friday after Federal Reserve Chairman Ben Bernanke said the central bank stood ready to bolster the economy if necessary, although he stopped short of giving an explicit signal of more monetary easing. Trading was volatile, and the S&P 500 briefly turned negative as investors appeared to be disappointed at first that Bernanke proposed no aggressive measures to restore vigorous growth.
But in his speech to central bankers in Jackson Hole, Wyoming, Bernanke spoke of his "grave concern" about the stagnation of the labour market, which seemed to turn the tide as stocks reversed course and climbed more than 1 percent before paring some of the gains.
The Dow Jones industrial average gained 81.11 points, or 0.62 percent, to 13,081.82. The Standard & Poor's 500 Index rose 6.60 points, or 0.47 percent, to 1,406.08. The Nasdaq Composite Index climbed 15.23 points, or 0.50 percent, to 3,063.94. Volume remained light, with about 2.69 billion shares traded on the New York Stock Exchange, NYSE Amex and Nasdaq with three hours remaining in the session. Daily average of volume is 6.53 billion.