US STOCKS SNAPSHOT-Wall St opens lower ahead of Fed policy meet, Instacart debut

Wall Street's main indexes opened lower on Tuesday ahead of the Federal Reserve's policy meeting, with investors awaiting grocery delivery app Instacart's Nasdaq debut to assess a potential recovery in the IPO market.

The Dow Jones Industrial Average fell 52.46 points, or 0.15%, at the open to 34,571.84. The S&P 500 opened lower by 8.12 points, or 0.18%, at 4,445.41, while the Nasdaq Composite dropped 60.79 points, or 0.44%, to 13,649.44 at the opening bell.