Cerebras Systems (CBRS) Stock Tumbles 7% Amid OpenAI-Nvidia Partnership Reports

Key Takeaways

• Cerebras Systems shares declined approximately 7% on September 30 following a SemiAnalysis industry report.
• The analysis suggests OpenAI’s GPT-6.1 Sol Ultrafast model operates on Nvidia hardware rather than Cerebras technology.
• OpenAI represents Cerebras’ most significant customer measured by revenue backlog.
• The Ultrafast tier’s performance reportedly reaches roughly 300 tokens per second, a decline from the previous model’s 750.
• CBRS shares have gravitated toward their 52-week low rather than their yearly peak.

Shares of Cerebras Systems tumbled roughly 7% to $181.40 during Wednesday’s trading session. The decline followed a report from semiconductor analytics firm SemiAnalysis indicating that OpenAI’s latest flagship artificial intelligence model isn’t utilizing Cerebras chip technology.

Cerebras Systems Inc., CBRS

According to the analysis, GPT-6.1 Sol Ultrafast operates on Nvidia infrastructure instead. This potentially encompasses Blackwell-generation processors like the GB300.

Both Cerebras and OpenAI have yet to provide official statements in response to media inquiries. The absence of formal confirmation leaves some ambiguity regarding the precise technical configuration.

The Impact on Cerebras

OpenAI stands as Cerebras’ most substantial client when measured by contracted revenue backlog. Any shift away from this key partnership carries disproportionate significance for investor confidence.

The chronology adds another layer of concern. This past August, Cerebras publicly declared it would support the Ultrafast tier for GPT-5.6 Sol, delivering performance reaching 750 tokens per second.

The announcement positioned this deployment as a major validation of the company’s proprietary Wafer-Scale Engine architecture. The recently introduced GPT-6.1 Sol Ultrafast tier, which OpenAI showcased at its DevDay event on September 29, allegedly operates at approximately 300 tokens per second.

This reduced throughput has sparked speculation about whether the expanded model dimensions are straining Cerebras’ on-chip memory architecture. Such technical considerations typically remain beneath investor radar, but this week proved different.

Mounting Headwinds for CBRS

Wednesday’s selloff represents just the latest challenge for the company. Cerebras has experienced considerable volatility following its initial public offering, which launched at $350 per share in May.

The semiconductor firm reported a GAAP net loss totaling $450.5 million during its latest quarterly disclosure. Company insiders have collectively divested approximately $266 million worth of shares across the previous three-month period.

Current trading levels place shares significantly nearer to their 52-week floor of $160.81 compared to their 52-week ceiling of $386.34. This substantial divergence illustrates how drastically market perception has evolved since the company went public.

The broader equity markets offered no support for Cerebras on Wednesday. Both the S&P 500 and the Nasdaq Composite posted gains, with the latter advancing 0.9%.

This divergence positioned Cerebras among the semiconductor sector’s most notable laggards for the trading day. Nvidia, by contrast, experienced upward momentum, appreciating roughly 2%.

An alternative interpretation suggests this development may not alter Cerebras’ long-term prospects. The company could potentially support future iterations of the Ultrafast configuration once infrastructure scaling or performance optimization challenges are resolved.

Nevertheless, market participants are responding to current developments rather than speculative scenarios. And the present narrative presents unfavorable optics for Cerebras.

As of Wednesday’s session, Cerebras stock traded near $181.40, representing a substantial retreat from its 52-week peak of $386.34. Neither organization has released additional commentary addressing the reported hardware transition.