March 5 (Reuters) - Wall Street's main indexes opened

lower on Tuesday, with the tech-heavy Nasdaq leading losses, as

megacap growth stocks fell ahead of a slew of economic data and

several key events this week, including appearances from Federal

Reserve Chair Jerome Powell.

The Dow Jones Industrial Average fell 82.85 points,

or 0.21%, at the open to 38,906.98.

The S&P 500 opened lower by 20.43 points, or 0.40%,

at 5,110.52, while the Nasdaq Composite dropped 129.77

points, or 0.80%, to 16,077.74 at the opening bell.