Is there uncertainty regarding the Fed's next round of quantitative easing?
''The Standard & Poor's 500-stock index shed seven points, or 0.6%, to 1152, led lower by energy and utility stocks. All 10 of the S&P 500 sectors traded in the red. The technology-heavy Nasdaq Composite fell nine points, or 0.4%, to 2411.
The morning pullback came after the Commerce Department said gross domestic product rose 1% during the April-to-June period, revised down from 1.3%, which matched Wall Street expectations. Investors were also keeping an eye on Hurricane Irene, which headed toward landfall on the East Coast.
The market will be zeroing in on Mr. Bernanke as he speaks at an economic symposium in Jackson Hole, Wyo., at 10 a.m. Eastern Time. Investors will be listening for clues on what the Fed is prepared to do if the economy continues to show signs of slowing.
Investors are unclear about what the central bank may have in store. Many are doubtful the central bank chief will announce a full-fledged third bond-buying program, commonly known as quantitative easing, or QE3.
'GDP was just another wake-up call that the economy continues to slowly deteriorate,' said Ryan Detrick, senior technical strategist at Schaeffer's Investment Research. 'The wild card is clearly Bernanke's comments. Unfortunately, the structural issues seem much bigger than what Bernanke can fix in his speech.'
Ahead of the speech, the final reading of August consumer sentiment is due out at 9:55 a.m.
In overseas markets, European stocks were broadly lower, with German stocks leading the fall. Asian bourses were mostly lower, led by weakness in Hong Kong.
Gold futures climbed to about $1,774 an ounce as investor anxiety prompted some moves back into the haven asset after a sharp selloff this week. Crude-oil futures slipped to around $84 a barrel. The U.S. dollar lost ground against both the euro and the yen.''