“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’s support page reads.

Reached for comment, Forge Global claimed to have been included erroneously. “We are working with Anthropic to remove Forge’s name from this alert,” the platform told TechCrunch. “Forge does not facilitate transactions in any private company’s shares without the explicit approval of the company.”

Forge on Tuesday added a new warning to its page on Anthropic, stating that any share sales not approved by Anthropic’s board will not be recognized on its books. The marketplace previously only said that users could buy the AI lab’s stock via Forge provided they were “accredited investors.”

Sydecar, meanwhile, said it only acts in an administrative capacity. “The company does not buy or sell securities or solicit transactions in any private companies. Further, Sydecar requires sponsors to attest that they have reviewed relevant documents relating to the transferability of shares and that they have the required approvals and consents from the company,” the company said in an emailed statement.