Steve Eisman, the investor immortalized in “The Big Short” for his prescient bet against subprime mortgages, has a new concern. This time it’s not collateralized debt obligations. It’s the entire foundation of Big Tech’s AI revenue engine.
In an appearance on CNBC’s “Fast Money,” Eisman laid out a blunt thesis: OpenAI and Anthropic together account for roughly 70% of AI-related revenue flowing to the major hyperscalers, including Microsoft, Amazon, Alphabet, and Oracle. That level of concentration, in Eisman’s view, is the “Achilles’ heel” of the AI trade.
Two companies, one massive dependency
That AI-driven revenue represents approximately 25-35% of these companies’ total cloud revenue. Cloud has been the growth story propping up premium valuations across the sector for years.
Microsoft, Amazon, Google, and Oracle have collectively poured hundreds of billions into AI infrastructure. The return on that investment is, to a remarkable degree, dependent on the continued spending and success of just two private AI labs.







