Semiconductor Stocks Tumble on Doubts Over AI Infrastructure Returns

Major chipmakers are selling off sharply as investors reassess whether massive artificial-intelligence spending by tech giants will ever justify the scale of current infrastructure investment. The Philadelphia Semiconductor Index has dropped 3% or more on multiple recent trading days, with declines accelerating after reports suggested OpenAI's annualized revenue fell to approximately $50 billion in September—well below the $70 billion figure previously cited. Nvidia, AMD, Broadcom, Micron Technology, and SK Hynix have all posted significant losses as concerns mount that the AI boom's pace may not sustain current valuations and growth expectations.