Wall Street's main indexes opened muted on Tuesday as investors refrained from placing big bets ahead of key economic data this week, including figures on job openings due later in the day that will provide further clues on the state of the economy.

The Dow Jones Industrial Average fell 28.86 points, or 0.08 percent, at the open to 34,531.12. The S&P 500 opened lower by 0.56 points, or 0.01 percent, at 4,432.75, while the Nasdaq Composite dropped 17.90 points, or 0.13 percent, to 13,687.23 at the opening bell.