Thursday was a day that will live in infamy for Alphabet shareholders, as the stock plunged 12.6%, vaporizing more than half a trillion dollars in value.
Why it matters: The massive one-day loss shows how AI continues to cause violent bouts of uncertainty throughout the markets, even for giants like Alphabet that have been considered big winners of the AI buildout.
Catch up quick: Alphabet's plunge followed lackluster third-quarter results posted Wednesday afternoon that seemed to suddenly raise questions not only about the extent of the company's spending on AI, but also about the durability of its core search advertising business.
What they're saying: Alphabet faces "unresolved if not intensifying competition risk from GenAI search products, including a potential Muse/Meta AI search product, as well as the threat of share loss to GenAI challengers," UBS analysts wrote in a note Thursday.