Tech selloff wipes out the S&P 500’s post-election bounce

The S&P 500 dropped 4.4% on Thursday, giving back the previous day’s post-election rally as investors sold technology shares. The Nasdaq fell 5.5%, with chipmakers and companies tied to the AI data-center buildout hit especially hard. The move reflects a bigger reassessment: much of the market’s recent optimism has rested on the expectation that enormous spending on AI infrastructure will translate into durable profits. That does not settle whether the AI boom will pay off, but it shows how quickly doubts about its pace or returns can pull down an index increasingly shaped by a relatively small group of tech giants.