First-quarter earnings of S&P 500 companies are expected to dip 2.2%, while revenues are seen declining 3.1%, according to Thomson Reuters data which includes companies that already reported.
"Equity investors have been selling this year while credit investors have been investing aggressively," said Brian Reynolds, chief market strategist at Rosenblatt Securities in New York.
"That tells me that in the second half of the earnings season we're going to see more buybacks and more mergers in response to the sell-off as CEOs are under pressure to jack up their stock prices."
Dow component Coca-Cola rose 2.80% to $41.92 after the world's largest beverage maker reported a rise in revenue for the first time in nine quarters, helped by more sales in North America, its biggest market.
Boeing fell 1% to $151.70 after the U.S. aircraft maker reported revenue that fell short of expectations.
Various companies have cited a negative effect of the strong U.S. dollar as a reason for cutting their forecasts. The dollar gained about 23% against a basket of major currencies over the financial year ended March 31, hurting companies with large overseas operations.
Chipotle shares fell 5.3% to $656 in premarket trading after the burrito chain on Tuesday reported the slowest same-restaurant sales growth in five quarters.
Angie's List jumped 16.6% to $7.20 and was the most actively traded stock premarket after the company posted a surprise profit.
Companies reporting results after the market close on Wednesday include AT&T <T.N>, Facebook <FB.O> and EBay <EBAY.O>.
Data expected to be released later on Wednesday include U.S. home resale numbers for March at 10:00 a.m. EDT.