Sam Altman posted on X on October 3 that OpenAI's relationship with Cerebras is strong, after a September 29 SemiAnalysis report that OpenAI was running GPT 6.1 Sol on NVIDIA-based platforms. Cerebras stock rose 10% on the post. Reporting since has added that Cerebras insiders, including the CFO and COO, have been dumping stock, and a new OpenAI model on Cerebras chips is rumored to run up to 20x faster at the same capabilities, possibly within days. The market is weighing the public reassurance against the insider selling and the unconfirmed speed claim.