Investors may be having second thoughts about Friday's big stock market rally.
U.S. stock futures were lower ahead of the opening bell Monday.
Marc Chandler, strategist for Brown Brothers Harriman, said that investors are in "wait-and-see mode" before Tuesday's Congressional testimony by Federal Reserve Chairwoman Janet Yellen.
This will be Yellen's first time testifying since taking control of the central bank this month. Investors will be watching to see if she sheds any light on plans to further taper, or slow down, the Fed's stimulus program.
Trading could be quiet Monday, with few major corporate or economic reports set for release.
Loews Corp (reported a worsening quarterly loss. )
Hasbro ( missed on earnings expectations and raised its dividend. Share slipped before the bell. )
Shares in Apple ( look like they may edge higher Monday as investors feel increasingly confident in the firm's stock buyback plan. )
European markets were narrowly mixed in morning trading.
Most Asian markets ended with sizable gains. The Nikkei in Japan was up 1.8% and the Shanghai Composite pushed up by 2%. But both of these indexes are still in negative territory since the start of 2014.