Stocks opened lower at the start of a week in which investors will learn how U.S. companies fared in the third quarter.
The Dow Jones industrial average was down 46 points, or 0.3%, to 13,564 shortly after the opening bell.
The broader Standard & Poor's 500 index was down 7 points, 0.5%, to 1,454. The Nasdaq was down 19 points, or 0.6%, to 3,117.
Third-quarter earnings season begins with aluminum giant Alcoa Inc., which announces Tuesday. JPMorgan Chase & Co. is up Friday.
Earnings overall are expected to disappoint. Analysts expect corporate earnings for companies in the S&P 500 to drop 2.4% from the same period a year ago, according to Thomson Reuters.
The ratio of companies that have pre-announced negative earnings-per-share (91) to those with positive pre-announcements (21) is at a level not seen since the third quarter of 2001, Thomson Reuters said.