Anthropic and OpenAI have updated their policies regarding stock, prohibiting secondary trading.

According to the first statement, any sale or transfer of securities without board approval is invalid: the buyer will not be recognized as a shareholder and will not receive any rights.

OpenAI's statement contains nearly identical wording: without written consent, the transfer of securities is invalid and holds no economic value.

Both companies listed the same types of transactions: direct sales, special purpose vehicles (SPVs), tokenized equity shares, and forward contracts.

SPVs are companies created to hold shares of a private firm and raise capital for their purchase. These structures have become a standard workaround for acquiring shares of non-public companies.

The vulnerability of this scheme lies in the ability to create "multiple levels of SPVs": additional companies to purchase shares of a similar structure. This complicates the verification of the legality of transactions involving the underlying shares.

Under the new rules from both companies, if the initial transfer of funds to an SPV is not approved by the board, the entire chain of transactions is deemed invalid.

Anthropic has published a list of specific blocked structures: Open Door Partners, Unicorns Exchange, Pachamama, Lionheart Ventures, Sydecar, Upmarket, Forge Global, and Hiive. The last two are the most well-known platforms for secondary trading of private company shares.

Forge Global is a regulated platform for accredited investors, where Anthropic's estimated valuation previously reached $1 trillion, surpassing OpenAI's $880 billion. The company stated that it was mistakenly included on the list.

"We are working with Anthropic to remove Forge's name from this warning. Our company does not facilitate transactions involving shares of any private companies without explicit approval from the firm," the comment read.

Market Reaction

The market reacted swiftly. Following the announcements from Anthropic and OpenAI, their tokens on PreStocks—a Solana-based platform—dropped from $1400 to $873 and from $2000 to $1080, respectively.

Source: Coingecko. Source: Coingecko

Over the past year, some crypto companies have launched investment products providing access to shares of private firms. These often take the form of perpetual futures—derivative instruments that track the value of private firms on secondary markets but do not confer ownership of actual shares.

Reasons for the Ban

In October 2025, OpenAI conducted a board-sanctioned tender offer: current and former employees were allowed to sell shares worth up to $30 million. Over 600 individuals collectively received $6.6 billion in a single transaction.

About 75 individuals opted to cash out the full $30 million. The company tripled the previous limit of $10 million per employee, as the old cap had caused dissatisfaction among leading researchers and developers.

OpenAI organized a campaign and approved each transaction—this is precisely the right that private firms seek to protect. They aim to control secondary sales, and the crackdown affects anyone trying to circumvent this.

Investors, on the other hand, are looking for access to the rapidly growing revenues of AI startups—those very loopholes that OpenAI and Anthropic have now closed.

Recall that in July 2025, OpenAI denied reports of launching tokenized shares of the firm, which were proposed by Robinhood.