Bill Ackman called Anthropic perhaps the greatest business story of his career but said Pershing Square is highly unlikely to invest before the AI company’s anticipated IPO. He cited Anthropic’s rapid revenue growth, Claude AI products, substantial losses and capital needs, while questioning whether leading AI companies can sustain competitive advantages as open-source and open-weight models develop. Confidential filing material reviewed by Reuters showed 2025 revenue rose twelve-fold to nearly $4.6 billion, while net losses reached $42 billion and planned cloud, computing and infrastructure obligations totaled $518 billion. Anthropic is reportedly seeking a valuation above $2 trillion and planning to list after the November midterm elections. The nearly 300-page filing devoted roughly one-third of its pages to risk factors, substantially more than the approximately 30 pages of warnings in SpaceX’s prospectus, Reuters reporter Echo Wang said. A Wall Street Journal report from August said Anthropic planned to project a $32.56 trillion total addressable market. Earlier accounts describing more than $500 billion in commitments and losses exceeding $50 billion across 2024 and 2025 have not been reconciled with the newer reported figures.