US stocks plunge on Black Thursday: S&P 500 sheds about $3 trillion in a day, Nasdaq enters technical correction

U.S. stocks suffered their sharpest tech sell-off in 19 months on Thursday, with the Nasdaq Composite plunging 5.52% into a technical correction, the S&P 500 falling 4.36%, and the Dow dropping 3.44%. S&P 500 components lost about $3 trillion in market value in a single day. The selloff centered on AI, semiconductor, and data center stocks, as investors worried that Democratic control of Congress after the midterm elections could bring stricter regulation and local resistance to AI infrastructure expansion. Nvidia fell more than 9%, and the Philadelphia Semiconductor Index tumbled over 12%. Federal Reserve rate hike expectations and Friday's nonfarm payrolls report remain key variables.