As investors across the board scramble to secure stakes in AI companies of every kind, Anthropic recently updated its website to caution that several private and secondary investment platforms claiming to offer shares in the company are not authorized to do so. The company specifically named Open Doors Partners, Unicorns Exchange, Pachamama Capital, Lionheart Ventures, Hiive, Forge Global, Sydecar, and Upmarket as entities that lack permission to facilitate the buying or selling of its shares.

"Any sale or transfer of Anthropic stock, or any interest in Anthropic stock, offered by these firms is void and will not be recognized on our books and records," the company stated in a blog post. This warning comes amid a surge in investment platforms providing exposure to AI company shares through secondary markets, where existing shareholders sell their stakes, as well as via "tokenized" securities, special purpose vehicles (SPVs), or secondary market holdings.

Over the past year, some crypto firms—such as the exchange OKX—have launched investment products that offer exposure to AI companies. These often take the form of pre-IPO perpetual futures contracts, which are derivative instruments tracking the value of private companies on secondary markets but do not grant ownership of actual shares. SPVs differ from these derivative systems, giving investors a chance to buy shares in an entity that holds at least some stake in Anthropic. That equity may come from an official investor or be acquired when an investor is forced to liquidate holdings, as happened during the FTX bankruptcy. In other cases, the equity claim could be entirely fraudulent.

Anthropic emphasized that both its preferred and common stock are subject to transfer restrictions, meaning any sale or transfer not approved by its board of directors will be considered invalid. The company further stated that any third-party platform—especially SPVs and retail investment firms—claiming to sell its shares directly or through forward contracts is unauthorized. "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," the blog post read. "Offers to invest in Anthropic’s past or future financing rounds through an SPV are prohibited."