A full breakdown of the OpenAI–Cerebras chip controversy

What happened: A SemiAnalysis post revealed OpenAI's GPT 6.1 Ultrafast runs on Nvidia (NVDA) chips rather than Cerebras (CBRS) chips, triggering a Cerebras stock plunge. Sam Altman then tweeted that Cerebras is a close partner. Key numbers: Nvidia worth around $5.7 trillion. Why it matters: The news hit Cerebras's core selling proposition of building the fastest chips, and the timing was bad as an early-investor unlock coincided with insider selling. Altman's tweet and the article's focus on GPT 6.1 only shifted sentiment.

A SemiAnalysis post revealed OpenAI's GPT 6.1 Ultrafast runs on Nvidia (NVDA) chips rather than Cerebras (CBRS) chips, triggering a Cerebras stock plunge. Sam Altman then tweeted that Cerebras is a close partner.

The news hit Cerebras's core selling proposition of building the fastest chips, and the timing was bad as an early-investor unlock coincided with insider selling. Altman's tweet and the article's focus on GPT 6.1 only shifted sentiment.