US equity indexes plummeted as investors assessed the impact on growth from the uncertainty accompanying President Donald Trump's 90-day pause on reciprocal tariffs and a tit-for-tat trade war with China, the world's second-largest economy.

The Nasdaq plunged 6.1% to 16,073.6, with the S&P 500 sliding 5.2% to 5,173.3 and the Dow Jones Industrial Average 4.4% lower at 38,824.7 in midday trading on Thursday. All sectors slumped intraday, with energy, technology, and consumer discretionary emerging as the steepest decliners.

The three mainstream indexes gave up a chunk of gains from a mega rally on Wednesday when Trump announced a pause on tariffs that came into effect at midnight on Tuesday. The president, however, excluded China from his global reprieve and instead increased the punitive import duties to 145%, reportedly including the 20% fentanyl trade levy set out earlier this year.

Trump has ratcheted up a trade war with China, brokerage D. A. Davidson said in a research note.

China will lower the number of US films allowed to enter the Asian country in response to the escalated tariffs imposed on Beijing by the Trump administration, China's National Film Administration said Thursday. Shares of Warner Bros Discovery (WBD) slumped 15% intraday, the worst performer on the Nasdaq.

The US economy is "still living on the edge," Morgan Stanley economists, including Michael Gapen, said in a note. The 90-day delay in reciprocal tariffs "reduces immediate downside risk, but prolongs uncertainty," Chief US Economist Gapen said. With the effective tariff rate at 23%, there is a "narrow gap between a slow growth outlook and a downturn" in the US.

CarMax's (KMX) fiscal Q4 earnings rose sharply year over year but missed Wall Street expectations, while the company suspended the timeframes related to its long-term objectives due to macro uncertainties. Shares sank 20% intraday, the worst performer on the S&P 500.

West Texas Intermediate crude oil futures plunged 4.9% to $59.32 a barrel.

Most US Treasury yields fell, with the 10-year yield down 3 basis points to 4.37% and the two-year slumping 14.7 basis points to 3.80%.