Wall St. ends down after energy slide, Yellen comments

Stocks added to losses after comments by Yellen, who told Congress the Fed expects the economy to continue to grow at a pace that returns inflation to policy-makers' target and that "if the incoming information supports that expectation ... December would be a live possibility" for a rate increase. "It's really that uncertainty - investors don't know whether to applaud a rate hike or to fear it," said Bruce Zaro, chief technical strategist at Bolton Global Asset Management in Boston.