Anthropic PBC has revised its public warning regarding secondary markets for its shares, cutting the number of platforms it labels as unauthorized by half following investor backlash and a sharp public response from one of the companies originally named in the notice.
The artificial intelligence company initially published a blog post identifying eight firms that it said were not authorised to facilitate the buying or selling of its shares due to transfer restrictions. In its original statement, Anthropic warned that any transactions conducted through these platforms would be considered void and would not be recognised on the company’s official shareholder records. The restriction applies to both preferred and common stock, reflecting the company’s effort to maintain strict control over transfers of its privately held equity.
In an updated version of the blog post, Anthropic reduced the list to four firms — Open Door Partners, Unicorns Exchange, Pachamama and Upmarket — removing several well-known names in the private secondary trading ecosystem. The revision represents a notable shift from its initial stance and has drawn attention across a market increasingly shaped by demand for access to high-growth artificial intelligence companies.
The decision follows confusion among investors after the original warning disrupted sentiment in secondary markets, where appetite for exposure to private AI firms has surged. Both Anthropic and rival OpenAI have long cautioned against unauthorised share transfers, though such warnings are often buried in legal disclosures and typically overlooked by investors eager to access pre-IPO equity. Anthropic’s move to publicly name specific platforms marked an unusual escalation that quickly spread across private trading circles.
Following the initial announcement, funds offering exposure to private technology companies experienced volatility, while brokers operating in secondary markets faced heightened scrutiny from investors questioning the legitimacy of transactions. The episode exposed ongoing uncertainty in private share trading, where regulation remains limited and enforcement mechanisms vary across platforms.
Among the firms originally named in Anthropic’s warning was Hiive, a secondary trading platform facilitating transactions in private company shares. Its chief executive officer, Sim Desai, responded on LinkedIn, stating that the platform does not enable share transfers “without the company’s approval,” emphasising compliance with issuer restrictions. After Hiive was removed from the revised list, Desai said the initial statement from Anthropic had caused confusion among investors and damaged the platform’s reputation.
“Had Anthropic approached us before their aggressive new stance and corresponding public statements (they did not), we would have gladly worked with them to deliver a unified message to the market,” Desai wrote on LinkedIn.
Anthropic did not immediately respond to a request for comment on the revision or the concerns raised by secondary market operators.
The dispute unfolds amid strong investor demand for Anthropic shares. The company raised $65 billion in a new funding round announced Thursday, valuing the artificial intelligence company at $965 billion including the new investment. The valuation placed Anthropic ahead of rival OpenAI for the first time, further intensifying demand for access to its equity.
As private AI companies remain out of public markets, secondary trading platforms have become a key channel for employees, early investors and institutional buyers seeking liquidity. At the same time, companies are increasingly tightening control over shareholder transfers to protect governance structures and manage valuation dynamics.
Anthropic’s revised warning reflects an effort to clarify its position while maintaining oversight of share transfers in a rapidly expanding private market shaped by artificial intelligence investment flows.
