Culper Research shorts Cerebras, alleging its wafer-scale chips fail in about two years

The short seller's report, titled "Hot Garbage," claims Cerebras hardware wears out far faster than the company's filings suggest Culper Research has a blunt message for Cerebras Systems investors: the company’s signature chips may not last as long as advertised. The short seller disclosed a position against Cerebras (NASDAQ: CBRS) on October 28, 2026, arguing that the company’s wafer-scale engines fail after roughly two years. The report carries a title that leaves little room for interpretation: “Hot Garbage.” What Culper is alleging Cerebras builds what it calls wafer-scale engines, or WSEs. Most chipmakers slice a silicon wafer into many small chips. Cerebras instead uses the wafer as one giant processor aimed at AI workloads. According to Culper, those engines typically last only 1.5 to 2.5 years. The company’s own filings, Culper notes, claim a useful life of 3 to 5 years. Culper also presented models suggesting that WSEs age 3 to 3.5 times faster than traditional GPUs. The root cause, per Culper, is heat. The report asserts that thermal expansion problems with the giant wafers have never been fully solved. Culper goes further with an unusual allegation. It claims Cerebras ha...