April 29 (Reuters) - Wall Street's main indexes opened higher on Monday as Tesla and Apple led gains in megacap companies, while investors exercised caution ahead of the Federal Reserve's interest rate decision later in the week.

The Dow Jones Industrial Average rose 42.5 points, or 0.11%, at the open to 38,282.16. The S&P 500 rose 14.2 points, or 0.28%, at the open to 5,114.13, while the Nasdaq Composite rose 79.1 points, or 0.50%, to 16,006.998 at the opening bell. (Reporting by Shristi Achar A in Bengaluru; Editing by Devika Syamnath)