Mumbai, Sept. 3 -- The tech-heavy Nasdaq slumped 175.92 points (0.8%) to 21,279.63 but had tumbled by as much as 1.5% in early trading. The S&P 500 slid 44.72 points (0.7%) to 6,415.54, while the Dow fell 249.07 points (0.6%) to 42,295.81.

Wall Street faced an early sell-off after a U.S. appeals court ruled most of Trump's global tariffs unconstitutional, though enforcement is delayed until October. Treasury yields spiked on fears the government may need to repay billions collected, while Trump insisted tariffs remain vital to the economy.

In U.S. economic news, the Institute for Supply Management released a report showing a slight increase by its reading on U.S. manufacturing activity in the month of August, although the index still in...