Cerebras stock rises 8% after Sam Altman calls chipmaker a close partner

Cerebras Systems Inc. stock rebounded on Monday, October 5, 2026, rising over 8% to $180.23 after OpenAI CEO Sam Altman reassured investors on X, calling the chipmaker a 'close partner.' The stock had plummeted 20% the previous week following reports that OpenAI's GPT-6.1 Sol would run on Nvidia GPUs instead of Cerebras hardware. Despite the recovery, Cerebras remains below its May 2026 IPO price of $185, with its market cap down to $39 billion from a peak of $95 billion.

Sam Altman's social media reassurance

• ▪OpenAI CEO Sam Altman's Friday, October 2, 2026, X post called Cerebras Systems Inc. a "close partner" with "deep engagement pushing on the frontiers of speed" without explicitly addressing if Nvidia graphics processing units power OpenAI's GPT-6.1 Sol
• ▪Cerebras Systems Inc. stock rose over 8% on Monday, October 5, 2026, trading at $180.23 as of 1:35 p.m. EDT, following a reassurance from OpenAI CEO Sam Altman, who called the chipmaker a "close partner"
• ▪Cerebras Systems Inc. stock rose approximately 3% in extended trading on Friday, October 2, 2026, immediately following Sam Altman's comments on X calling Cerebras a "close partner"

SemiAnalysis report on OpenAI hardware

• ▪Cerebras Systems Inc. shares fell 20% during the week ending Friday, October 2, 2026, closing at $166.43, after SemiAnalysis reported that OpenAI's GPT-6.1 Sol is running on Nvidia graphics processing units instead of Cerebras hardware
• ▪Nvidia's official X account responded to the SemiAnalysis report regarding OpenAI's GPT-6.1 Sol deployment with an eyes emoji

Cerebras contracts with OpenAI

• ▪Cerebras Systems Inc. signed a deal with OpenAI in January 2026 to supply 750 megawatts of computing power through 2028, valued at over $10 billion
• ▪OpenAI reportedly agreed in April 2026 to pay Cerebras Systems Inc. over $20 billion over three years to use servers powered by Cerebras chips

Cerebras initial public offering

• ▪Cerebras Systems Inc. went public in May 2026, pricing 30 million shares at $185 and raising $5.5 billion at a fully diluted valuation of $56.4 billion
• ▪Cerebras Systems Inc.'s market capitalization fell to just over $39 billion by October 5, 2026, down from $95 billion during its initial public offering debut in May 2026
• ▪On its first day of trading in May 2026, Cerebras Systems Inc. stock opened at $350 and closed at $311.07, representing a 68% increase from its $185 initial public offering price

Debatable claims

• ▪Frontier AI companies including OpenAI, Google, Anthropic, and Meta remain heavily reliant on advanced graphics processing units manufactured by Nvidia to train and run their models
• ▪OpenAI's deployment of GPT-6.1 Sol on Nvidia chips is a major setback for Cerebras
• ▪Sam Altman's public reassurance is sufficient to restore long-term investor confidence in Cerebras