Anthropic warns investors against unauthorized secondary share sales on eight platforms

Anthropic warned investors in the week ended May 13, 2026, that eight investment platforms are not authorized to trade its shares, seeking to curb secondary-market sales tied to tokenized securities and special-purpose vehicles. The company named Open Doors Partners, Unicorns Exchange, Pachamama Capital, Lionheart Ventures, Hiive, Forge Global, Sydecar and Upmarket. Anthropic said any transactions in its stock or equity interests initiated by those entities are invalid and will not be recognized or recorded on its shareholder register. The warning follows strong demand for Anthropic shares after a new funding round reportedly lifted its valuation to $900 billion. Forge Global said it was incorrectly listed and is working with Anthropic to remove the notice, adding it has not facilitated private-company share trades without explicit issuer approval. Sydecar said it provides administrative services only and does not buy, sell or solicit securities transactions.