US stock indexes gained at the open on Wednesday as a pickup in business activity fueled hopes of a post-pandemic economic recovery, while investors remained cautious about brewing US-China tensions.

The Dow Jones Industrial Average rose 303.52 points, or 1.21 per cent, at the open to 25,298.63.

The S&P 500 opened higher by 23.88 points, or 0.80 per cent, at 3,015.65, and the Nasdaq Composite gained 5.90 points, or 0.06 per cent, to 9,346.12 at the opening bell.