The Strange Reason for Arm’s Stock Drop: The Market May Be Punishing It Unfairly

Arm Holdings (ARM) stock dropped nearly 10% in one day, one of the sharpest falls in the chip space on Sept. 14. The reason was the same AI selloff that hit the whole sector. The selloff started with an essay from Anthropic CEO Dario Amodei arguing that AI development should slow down. Amodei argued the technology is advancing quicker than humans' ability to control it. The weight of this statement increased further when SpaceX (SPCX) CEO Elon Musk and OpenAI CEO Sam Altman agreed soon after. Investors read that as a threat to AI spending and sold off stocks tied to the theme. Arm was treated as a prime AI name and punished accordingly.

The problem with that reaction is that Arm isn’t really an AI company yet — at least not in terms of where its money comes from. Arm licenses its chip designs and earns a royalty on nearly every chip that ships using them. A large share of that still comes from smartphones. Mobile processors are Arm’s single-biggest source of royalties, coming in at about 43% in fiscal 2026. No other market comes close. The company’s own AI chip, the AGI CPU, is still early in its commercialization and won't become a meaningful revenue contributor until fiscal 2028.