S&P 500, NASDAQ END down as Banks, Tech Weigh

The S&P 500 and NASDAQ ended slightly lower and the Dow was flat, reversing earlier gains, after comments by Federal Reserve Chairman Ben Bernanke sparked jitters about the economic recovery.

Financial and technology shares were among the biggest drags on the market. The S&P Financial Index lost 1.6% while the KBW Bank (KBW) Index shed 2.1%.

Speaking at the Economic Club of Washington, Bernanke said inflation could remain subdued, but the U.S. unemployment rate could remain elevated for some time. Initially the Fed chief's remarks lifted stocks and sent the dollar lower, but later some investors pared positions.

Bernanke said the U.S. economy faces "formidable headwinds," including a weak labor market and tight credit conditions that have persisted despite the Fed's efforts to support the economy