The Dow Jones Industrial Average surged 7.9 per cent to 40,608.45 and the broad-based S&P 500 Index rallied 9.5 per cent to 5,456.90.
The tech-focused Nasdaq Composite Index jumped 12.2 per cent to 17,124.97.
All three indexes bounced on Wednesday afternoon as Trump announced a 90-day pause in country-specific tariffs that came into place earlier that day, except levies on Chinese goods.
Affected US trading partners excluding China would instead face a 10 percent tariff rate, temporarily reverting to a level that took effect over the weekend, though that already roiled markets.