U.S. stocks ended slightly lower Monday as investors looked ahead to earnings season. Aggregate first-quarter S&P 500 earnings are estimated at $26.17, representing a decline of 8.1 percent year-over-year, for the third quarterly decline in a row, according to a Friday note from Lindsey Bell, senior analyst at S&P Global Market Intelligence. "Such a steep decline in growth hasn't been recorded since second-quarter 2009," she said.
Hopes that oil producers will agree to freeze output have supported crude prices, with Brent trading around $43 a barrel and U.S. crude at near $40.70 a barrel.
Alcoa kicked off earnings season on Monday. The group was hurt by weak aluminum prices and sales missed. The stock was down over 4 percent in premarket trade.
March export prices were unchanged, while import prices showed a 0.2 percent rise from the prior month.
At 2 p.m. the monthly Federal Budget statement is due for release.
Railroad operator CSX reports earnings after the bell.
Philadelphia Fed President Patrick Harker, San Francisco Fed President John Williams and Richmond Fed President Jeffrey Lacker are due to speak on Tuesday.
Dallas Fed President Rob Kaplan has said it is too soon for an interest rate hike in the United States, but he is open to a rate hike in June.
Speaking on CNBC's "Squawk Box" Tuesday morning, Kaplan said the U.S. economy is likely to grow at just under 2 percent for the year. He also said the financial turmoil at the beginning of the year may have had more of psychological impact on consumers than previously thought.