Key points
- Cerebras now trades below its IPO price
- A report says OpenAI's Ultrafast mode runs on Nvidia
- More insider shares can be sold from Oct. 14
Cerebras Systems (CBRS) ended the week at its lowest closing price since its May IPO, down 19.5% to $166.43. That puts the stock about 10% below its $185 offering price. During the week, a report linked OpenAI's GPT-6.1 Sol "Ultrafast" mode to Nvidia (NVDA) hardware, while another batch of Cerebras shares became eligible for sale under its IPO lockup schedule.
Research firm SemiAnalysis posted on X after the market closed on Sept. 29 that the mode "is NOT running on Cerebras but is instead running at a low batch size on NVIDIA GPUs." Nvidia's AI account replied with an eyes emoji. Cerebras shares fell 8.9% the next day.
OpenAI Chief Executive Sam Altman defended the partnership in an X post at about 6:20 p.m. ET on Oct. 2. "There is some speculation about our partnership with Cerebras. Cerebras is a close partner, and we have a deep engagement pushing on the frontiers of speed," he wrote. He did not identify the hardware powering Ultrafast. Cerebras shares rose about 3% in after-hours trading following his post.
Cerebras has a $10 billion-plus OpenAI deal
Cerebras makes dinner-plate-sized AI chips. It sells systems built on them for customers to run on their own premises and also rents out computing power through its own cloud, according to its prospectus. In January, it agreed to supply OpenAI with 750 megawatts of computing power through 2028 in a deal worth more than $10 billion.
The stock opened at $350 on its first day of trading in May and closed that day with a market value of about $95 billion. It's now down more than 50% from that opening price, and its market value is just over $39 billion.
More insider shares unlock on Oct. 14
Cerebras has been releasing insider shares from its lockup in stages, according to its IPO prospectus. Up to about 14.6 million shares became eligible for sale every two weeks from Aug. 19 through Sept. 16, and up to about 19.4 million more on Sept. 30. Up to about 19.4 million more can be sold starting Oct. 14, and the same number again on Oct. 28. The rest unlock on the second trading day after Cerebras reports third-quarter earnings, or 180 days after the date of the prospectus, whichever comes first.
Executives have been selling. Chief Operating Officer Dhiraj Mallick sold 396,000 shares for about $80.8 million on Sept. 29, and Chief Financial Officer Robert Komin sold about $6.6 million the same day, according to their Form 4 filings. Both sales were made under trading plans adopted on June 30. Insiders had already sold $296 million of stock between June and early September.
