Steve Eisman said the artificial intelligence boom has become unusually concentrated around OpenAI and Anthropic, arguing that the two startups account for roughly 70% of AI-related revenue at Microsoft, Amazon, Alphabet's Google and Oracle and about 25% to 35% of those companies' cloud revenue. Speaking on CNBC's "Fast Money" late Tuesday, he said the outlook for those large technology groups is effectively tied to whether the two AI developers continue to succeed. Eisman said the biggest risk may come from China, where cheaper open-source AI models (software released for broad use and modification) appear to be gaining market share, a shift that could trigger a price war across cloud and AI services. His comments add to a wider debate over whether the heavy spending driving the AI boom can produce adequate returns. Michael Burry has taken a more bearish stance, questioning whether much current and future AI demand reflects genuine end-customer demand or financing through what he described as circular arrangements, and has disclosed bearish positions against Nvidia and the broader semiconductor sector.