About 30 minutes into trading, the Dow Jones Industrial Average slipped 0.1 percent to 24,759.60, weighed down by a weak forecast from IBM. The tech-rich Nasdaq Composite Index also shed 0.1 percent to 7,273.24.
The broad-based S&P 500 rose 0.1 percent to 2,708.11.
Strong earnings from Netflix, Johnson & Johnson and several large banks have helped Wall Street advance this week, pushing to the side uncertainties over US-China trade relations and monetary policy that have pressured prices.
But those gains began to peter out as the trading session opened, due in part to a disappointing forecast from IBM.
Dow member IBM sank 6.4 percent after it projected full-year earnings of "at least $13.80" a share, which was below many analysts' expectations.
But Morgan Stanley gained 2.7 percent after reporting a 39.9 percent jump in first-quarter earnings to $2.6 billion. Other large banks also shook off recent weakness and rose higher, including JPMorgan Chase and Goldman Sachs.
Airline shares also were higher after better-than-expected results from United Continental, which advanced 2.3 percent. Southwest Airlines gained 1.8 percent as investigators probed an emergency landing on a flight Tuesday that led to a fatality.