The Fed chief will appear before the Senate Banking Committee at 10 a.m. Eastern time. Bernanke sent a number of negative signals Wednesday during testimony to the Joint Econoomic Committee, making clear that he thinks a recession may already be under way.

If Bernanke reiterates those sentiments Thursday, there could be selling throughout the session. Many economists previously have said they think the economy is shrinking, but the Fed chairman carries special weight with investors and his pronouncements can influence the market.

New data reports also could influence the direction of trade. At 8:30 a.m., the Labor Department will release the latest weekly jobless claims tally, a day before the much-awaited March employment report comes out. According to Thomson/IFR, the number of claims should decline to 356,000 from 366,00 a week before.

In addition, the Institute for Supply Management will put out its March survey of the services sector at 10 a.m. That poll is expected to produce a headline reading of 50.1, which would represent an improvement over 49.3 in February. All readings over 50 indicate expansion so the projected result would indicate that the services sector has begun to grow again.