US stocks plunge 6.4% as Democratic win threatens AI investment

US stocks fell sharply Thursday, with the tech-heavy Nasdaq 100 plunging 6.4%, after the Democrats' sweeping midterm election victory raised fears about the future of AI investment. The broad S&P 1500 Composite lost $3.2 trillion in market value. The sell-off was driven by concerns that the new Democratic majority will slow AI spending, which has powered Wall Street to record highs this year. Nvidia tumbled 9.3%, losing over $400 billion in market value, while the S&P 500 fell 4.4% in its worst session since April 2025. Investors fear newly elected politicians, including senators who proposed pauses on frontier AI development and bans on new data centers, will curb infrastructure spending. Chipmakers were hit hard, with Qualcomm down 9.5%, Broadcom down 10%, and Micron down 17%, while Tesla and SpaceX also fell sharply.