Stock futures point to a cautious open as investors prepare for Janet Yellen's second day of congressional testimony: Dow -0.1%, S&P -0.2%, Nasdaq -0.5%.
European markets are higher after the ECB announced no changes to its policy stance, but Mario Draghi said the bank is ready to act in June "if needed."
Reaction was muted to a drop in U.S. weekly jobless claims to the lowest level in a month, but the decline likely stemmed from seasonal quirks instead of any major change in hiring trends or layoffs.
Treasurys hover near their morning highs, with the 10-year yield off one basis point at 2.61%.
Still ahead: EIA natural gas.