Cerebras stock surges after OpenAI CEO Altman lauds 'close partner'

Cerebras ( CBRS ) stock rose 9% on Monday after OpenAI ( OPAI.PVT ) CEO Sam Altman reaffirmed the AI lab's partnership with the AI chipmaker.

"Cerebras is a close partner," Altman posted on X, "and we have a deep engagement pushing on the frontiers of speed."

Cerebras shares have been under pressure since mid-August, when the company reported disappointing earnings and guidance.

Altman's tweet came after discussion related to OpenAI's GPT‑5.6 Sol on Ultrafast mode , which runs on Cerebras chips, and usage by quant trading firm Jane Street.

Cerebras Systems went public in May , entering an AI chip market dominated by Nvidia ( NVDA ), and is known for its massive chips.

OpenAI, which is eyeing an IPO as early as next year, is reportedly targeting new funding that would value the company at $1.4 trillion.