Alphabet shares plunge 15.8%, wiping out $550 billion in market value

Alphabet's stock plunged up to 15.8% on Thursday, erasing over $550 billion in market value, marking its worst single-day drop ever and the second-largest in market history. The sell-off followed Wednesday's quarterly earnings report, which showed revenues and advertising sales fell short of Wall Street expectations. JPMorgan analysts noted the slowdown in Google's search business was "steeper than expected," partly due to its own AI Mode feature reducing ads. Alphabet has committed to over $1 trillion in multi-year AI infrastructure spending, with more than $200 billion planned this year. The drop dragged down the Nasdaq and hit AI-related stocks, including chipmakers and Caterpillar, amid broader investor anxiety over AI investment returns.