Nine out of 10 groups in the S&P 500 rose, as consumer discretionary, industrial and financial stocks erased earlier losses. The S&P 500 had added 0.6 percent to 1,410.04 as of 1 p.m. Eastern time and the Dow Jones industrial average had risen 77.16 points, or 0.6 percent, to 13,134.62. 

Bernanke wrote in an  Aug. 22 letter to California Republican Darrell Issa, the chairman of the House Oversight and Government Reform Committee, that “There is scope for further action by the Federal Reserve to ease financial conditions and strengthen the recovery.” 

“It’s summer trading and volume is light so it doesn’t take much to move the market. A little whiff of positive news was enough,” he said. 

Minutes from the Federal Open Market Committee’s July 31- Aug. 1 meeting showed that many members judged that more stimulus “would likely be warranted fairly soon” unless the pace of the recovery picks up. 

Bernanke will have an opportunity to clarify his views in his Aug. 31 speech at Jackson Hole, Wyo., where he signaled a second round of bond buying in 2010.