Nvidia rival Cerebras jumped 12%, then crashed 18%: what went wrong?

Cerebras Systems stock NASDAQ:CBRS whipsawed on Wednesday after investors cheered the Nvidia challenger before earnings, then punished it once the numbers arrived.

The stock jumped 11.6% during the regular session to $262.06, only to fall about 18% in extended trading.

Core revenue more than doubled, cloud revenue nearly quadrupled and management raised its full-year outlook.

The problem was not demand. Cerebras is spending heavily to add computing capacity fast enough to serve customers, squeezing margins when its valuation leaves little room for disappointment.

Earnings were stronger than the stock reaction suggests

Cerebras reported core revenue of $209.9 million, up 103% year on year and above guidance.

Core cloud and services revenue rose 287% to $127.7 million as OpenAI deployments and customer usage expanded.

GAAP revenue was $180.1 million, below Wall Street’s roughly $194 million expectation.

Cerebras also lifted full-year core revenue guidance to $880 million-$890 million and said it plans to more than triple revenue in 2027.

That makes the sell-off harder to explain as a simple earnings miss.

Morgan Stanley had made a similar point after Cerebras’ previous post-earnings decline.

Analysts said “nothing in these numbers was disappointing,” while arguing management’s forecasts could prove conservative.

The latest results leave the same tension intact, as customers want Cerebras technology, but investors increasingly want evidence that growth will translate into stronger economics.

Booming AI demand is creating a margin problem

The clearest pressure point is gross margin.

Core gross margin fell to 40.6% from 46.5% in the first quarter. Cerebras said it is temporarily renting systems back from cloud customers to meet inference demand while its own data-centre capacity comes online.

That serves customers sooner, but makes current revenue more expensive.

Management expects core gross margin to fall further to 38%-40% in the third quarter before improving significantly in Q4 as more Cerebras-owned systems become available.

Wedbush analyst Matt Bryson had warned that Cerebras carried “almost zero demand risk”, according to MarketWatch, but that expectations would be dictated by execution.

TD Cowen similarly said margins would be pressured as Cerebras aggressively ramped capacity.

That argument now looks central. Cerebras may have more demand than its present infrastructure can efficiently handle.

For investors following the stock through investment apps, the question is no longer whether customers are arriving. It is how quickly Cerebras can add capacity without giving away too much profitability.

A $25 billion backlog raises expectations even higher

Cerebras ended June with $25.4 billion of remaining performance obligations, an enormous contracted revenue pipeline for a newly public AI company.

Yet Barron’s noted that backlog was broadly unchanged from the previous quarter. For a stock that had already surged nearly 12% before earnings, investors may have wanted another major step-up.

The company still has powerful growth levers. It has more than 600 megawatts of data-centre capacity live or under contract through 2027, plans to expand manufacturing capacity more than tenfold this year and counts OpenAI, AWS, AMD and CrowdStrike among partners or customers.

Its balance sheet is strong after the IPO, with $8.6 billion of cash, restricted cash and short-term investments at quarter-end.

But demand is only half the equation. Cerebras has shown that its wafer-scale architecture can attract major AI customers. What it has not yet shown is that explosive demand can be converted into explosive profits.