Alphabet shares plunge 12% on AI spending fears, erasing $500 billion in market value

Alphabet shares plunged over 12% on Thursday, its steepest single-day drop since its 2004 listing, erasing roughly $500 billion in market value after third-quarter results showed free cash flow unexpectedly turned negative and search ad growth missed expectations. The selloff reflects mounting investor alarm over massive AI spending and unclear returns. Alphabet reported negative free cash flow of $9.07 billion for the quarter, versus analyst forecasts of positive $2.7 billion, while maintaining its full-year capital expenditure guidance of $195 billion to $205 billion. Microsoft, by contrast, saw shares hold roughly flat despite heavy AI investment, as its free cash flow remained positive and capital spending came in below estimates. Analysts cited Alphabet's messy results, weak management communication, and slower AI commercialization—including lower-than-expected search ad revenue of $63.35 billion, up 12% year over year—as key factors. Some analysts argue Alphabet's roughly 4 billion global search users remain a long-term advantage, and that AI monetization challenges affect the entire consumer AI industry, not just Google.