Sam Altman's Cerebras Stake Worth ~$30M After Blockbuster IPO

Sam Altman scored a massive personal windfall Thursday as Cerebras, the AI chipmaker in which he holds a personal stake, launched the year's largest IPO. Cerebras stock opened at $350 per share — nearly double its $185 IPO pricing — turning what was a modest paper holding into a potential ~$30 million position for the OpenAI CEO.

Court documents from Altman's ongoing litigation against Elon Musk revealed he held 89,373 Cerebras shares valued at $3.2 million at year-end 2024. Altman originally acquired his interest in February 2017 — eight years before the IPO and well before the AI boom made inference-optimized chips a hot commodity. Cerebras, led by CEO Andrew Feldman, builds unusually large wafer-scale chips specifically designed for AI workloads, and has pivoted hard toward inference — the process of running AI models to answer user queries in real time.

The relationship between Cerebras and OpenAI has grown far beyond Altman's personal bet. In January, the two companies announced a deal valued at over $10 billion: OpenAI will use Cerebras chips, co-develop future technology with the company, and has the option to purchase additional chip batches through 2030. OpenAI also extended Cerebras a $1 billion loan and received warrants for millions of shares upon the IPO — meaning both Altman personally and OpenAI as a corporation stand to benefit from Thursday's rally.

Cerebras' own IPO prospectus candidly acknowledged that its first two chip generations, released in 2020 and 2022, generated little excitement. The launch of ChatGPT changed that trajectory dramatically, and inference demand has since exploded. Altman himself appeared in a promotional video for the IPO calling Cerebras' chips the top high-speed inference offering on the market — a notable endorsement given his simultaneous role running OpenAI, one of the company's biggest customers.