Anthropic flags unauthorized secondary-market sellers of shares

Anthropic updated an investor-warning page identifying eight secondary-market platforms it says are unauthorized to buy or sell its private shares, according to reporting by Bloomberg, Coindesk, and CryptoBriefing. The company told prospective buyers that unapproved sales or transfers of its stock, including interests in its stock, "are void and will not be recognized" on Anthropic's books, per Coindesk's reporting of the notice. The update explicitly warns that transfers through special purpose vehicles (SPVs) are prohibited and quotes Anthropic stating, "We do not permit special purpose vehicles (SPVs) to acquire Anthropic stock and any transfer of shares to an SPV are void under our transfer restrictions," as reported by Coindesk.

According to Bloomberg and Economic Times coverage of the updated post, platforms called out include Hiive, Forge Global, Open Door Partners, Unicorns Exchange, Pachamama, Sydecar, Lionheart Ventures, and UpMarket. Bloomberg and CryptoBriefing report Anthropic also warned against tokenized offerings and other mechanisms that claim to provide access to its shares.

The Block reports that Solana-based tokenized PreStocks tied to Anthropic and OpenAI fell sharply after the companies issued notices; The Block cites CoinGecko data showing declines of roughly 38% for Anthropic-linked PreStocks and 46% for OpenAI-linked PreStocks. Economic Times and Bloomberg cite statements from platform representatives: a Forge spokesperson said Forge is working with Anthropic to remove the firm from the alert, and a Hiive spokesperson said share transfers facilitated by Hiive are approved by issuers, per Economic Times.

Tokenized pre-IPO products and SPV-based offerings typically attempt to create tradable exposure to private-company equity without immediate issuer approval. Industry reporting (Coindesk, The Block) highlights two common structures: synthetic instruments that reference a private-company price and tokenized or SPV-based structures that claim to hold or represent underlying shares. Companies subject to transfer restrictions and board approval requirements can enforce contractual limits that prevent cap-table changes absent consent, which is why Anthropic's notice emphasizes void transfers.

Observers following private markets and crypto-based secondary trading note a broader pattern where heightened retail demand for pre-IPO exposure has spawned intermediaries that sometimes operate in legal and operational gray areas, as reported by Coindesk and Bloomberg. For practitioners and platform operators, this episode underlines the gap between market-available instruments and enforceable corporate governance rules; secondary pricing in tokenized markets can therefore disconnect from legally transferable ownership.

Industry watchers will track whether named platforms remove listings or change disclosures, whether secondary prices for Anthropic-linked instruments continue to diverge from private market estimates, and whether any legal or regulatory actions follow, per reporting dynamics in Bloomberg, The Block, and Coindesk. Analysts and platform compliance teams will also watch for similar notices from other private companies as tokenized pre-IPO products proliferate.

Anthropic's public warning, documented in multiple outlets including Bloomberg and Coindesk, clarifies that the company does not recognize unapproved share transfers and flags SPVs and tokenized securities as likely invalid mechanisms for obtaining enforceable equity claims. Industry reporting shows immediate market effects on tokenized instruments and public rebuttals from at least some named platforms, underscoring the legal and operational tensions between secondary-market innovations and corporate transfer restrictions.