Major U.S. stock indexes mixed on Wednesday as Apple's disappointing forecast and oil prices comeback, ahead of the Federal Reserve's statement on monetary policy.

Apple's shares were down 4% after the company also reported its slowest-ever rise in iPhone shipments on Tuesday. The stock was the biggest influence on the S&P 500 and the Nasdaq.

Oil futures turned higher after trading down as much as 4%, near $30 a barrel as data showed a jump in weekly demand for products such as heating oil when a cold front hit the country, although analysts said the rise in prices may not last long.

Almost all of Dow stocks in positive area (24 of 30). Top looser - The Boeing Company (BA, -6,68%). Top gainer - The Goldman Sachs Group, Inc. (GS, +2,46%).

Almost all S&P sectors also in positive area. Top gainer - Basic Materials (+1,6%).

At the moment:

Dow 16121.00 +55.00 +0.34%

S&P 500 1905.50 +9.50 +0.50%

Nasdaq 100 4206.50 -20.25 -0.48%

Oil 32.73 +1.28 +4.07%

Gold 1117.40 -2.80 -0.25%

U.S. 10yr 2.04 +0.05