AI stock selloff drags S&P 500 down 3.5% in worst drop since April

A major selloff in AI-related stocks sent the S&P 500 tumbling 3.5% on Thursday, erasing all gains from the previous session and marking its worst drop since April 2025. The decline was led by Nvidia, which fell 7.5%, while Advanced Micro Devices dropped 14.6% and CoreWeave lost 12.1%. Losses were broad across all sectors, triggered by concerns that high borrowing costs and Democratic victories in Tuesday's midterm elections could slow AI data center construction. The selloff hit global markets, with South Korea's Kospi plunging 5.3% and Japan's Nikkei 225 sinking 1.8%. Treasury yields eased to 4.83%, while Brent crude rose 2.6% to $97.11 amid ongoing uncertainty over the Iran war.