"Though much of her testimony will be similar to her February 11 appearance at the House Financial Services, there have been a few more data releases since that day and markets will be wondering what she has to say on the weather-effect now that the worst of the storms appear to have passed," said Deutsche Bank's Jim Reid and Anthony Ip in a note.
Earnings due before the start of Wall Street trade on Thursday include LKQ, Mylan Labs, Ocwen and Sempra Energy.
(Track: European markets live)
On Wednesday, the blue-chip Dow finished 0.2 percent higher. The S&P 500 and the Nasdaq also squeezed out small gains, with the latter briefly hitting a 14-year high.
—By CNBC's Katy Barnato