Tech stocks log worst day since 2020 as carnage comes to the AI trade

MarketWatch · Tomi Kilgore, Joy Wiltermuth · 2026-11-05 21:45 UTC

S&P 500 loses an estimated $2.9 trillion in market capitalization, the largest one-day loss of market value on record

S&P 500 loses an estimated $2.9 trillion in market capitalization, the largest one-day loss of market value on record

Stocks endured a broad beating on Thursday, unlike anything seen in years, as fears of an end to the artificial-intelligence trade compelled investors to sell first and ask questions later.

In the aftermath of the S&P 500’s SPX worst day since the panic that greeted President Donald Trump’s “liberation day” tariff announcement in April 2025, the first question is, what happened?

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