In a decisive move that sends ripples through the burgeoning secondary market for private tech shares, artificial intelligence giants Anthropic and OpenAI both updated their stock transfer policies on Tuesday, issuing a clear and unambiguous message: investments made through unauthorized channels may render buyers with nothing more than a valueless piece of paper. The companies’ parallel statements signal a significant tightening of controls over the trading of their highly sought-after private equity, aiming to curb what they perceive as illicit and potentially fraudulent transactions.
Anthropic’s updated policy page explicitly states that any sale or transfer of its stock without the explicit approval of its board of directors is considered "void." This is not a distinction of being voidable or disputable, but rather a declaration of absolute nullity. Under this new framework, any individual or entity attempting to acquire Anthropic shares through unapproved means would not be recognized as a shareholder and would consequently possess no associated rights or claims. OpenAI’s accompanying statement echoes this sentiment with nearly identical language. Any transfer of its equity conducted without written consent is deemed void, meaning "the sale will not be recognized and carry no economic value to you."
Both leading AI firms have specifically identified a range of prohibited transaction methods, including direct sales between parties, the use of Special Purpose Vehicles (SPVs), tokenized interests, and forward contracts. This broad sweep indicates a comprehensive effort to regain control over the flow of their private shares, particularly in light of soaring valuations and intense investor interest.
The Rise of SPVs and the Complications They Entail
Special Purpose Vehicles (SPVs) have become a prevalent mechanism in the private secondary market. Essentially shell companies created for a singular purpose, SPVs in this context are designed to hold shares in private companies, thereby pooling capital from external investors. Since direct transfers of shares typically require company board approval, which can be a slow and restrictive process, SPVs emerged as a workaround. An SPV would acquire a block of shares from the company or existing shareholders, and then investors would purchase stakes in the SPV, effectively gaining indirect exposure to the underlying equity.
However, the very nature of SPVs, particularly when layered, introduces significant complexity and potential for opacity. As PitchBook analyst Emily Zheng has described, this layering can involve "multiple layers of SPVs that create multiple layers of management fees." This nesting of entities means each SPV layer can charge its own fees, further obscuring the origin and legitimacy of the underlying shares. The core issue, as highlighted by the new policies from Anthropic and OpenAI, is that if the initial transfer of shares into any SPV lacked the necessary board approval, the entire chain of subsequent transactions becomes void. This effectively invalidates all investments made through such convoluted structures, regardless of how many layers are involved.
Anthropic’s Blocklist: A Direct Blow to Marketplaces
Anthropic has taken its policy enforcement a step further by publishing a specific "blocklist" of entities and platforms where unauthorized transactions have reportedly occurred or are being facilitated. This list includes names such as Open Door Partners, Unicorns Exchange, Pachamama, Lionheart Ventures, Sydecar, and Upmarket. Crucially, the list also names new offerings on Forge Global and Hiive, two of the most established and reputable marketplaces for trading private company shares.
This inclusion of regulated secondary market platforms is particularly significant. Forge Global, for instance, is a platform where accredited investors can legally trade shares in private companies. As previously reported, Anthropic’s implied valuation on Forge had reached an astonishing $1 trillion, surpassing OpenAI’s $880 billion valuation on the same platform, according to figures confirmed by Forge CEO Kelly Rodriques. Anthropic’s decision to include Forge and Hiive on its blocklist signifies that it is not differentiating between informal gray-market schemes and established, regulated marketplaces. The company’s stance is that any transfer without board approval is void, irrespective of the venue. This places buyers on platforms like Forge and Hiive in a precarious position, facing the same uncertainty as investors in less formal arrangements.
The immediate impact on the tokenized market has been palpable. The Anthropic token on PreStocks, a Solana-based platform leveraging SPVs, saw a dramatic price drop from $1,400 to $900 following Anthropic’s announcement, according to data from Coingecko. OpenAI’s equivalent token experienced an even sharper decline, crashing from $1,400 to $900 within a 24-hour period. This illustrates the market’s sensitivity to regulatory clarity and the companies’ commitment to enforcing their transfer policies.
Clarifying Authorized Transactions: The OpenAI Employee Sale
The stringent policies enacted by Anthropic and OpenAI may raise questions for those unfamiliar with the intricacies of private equity markets. A pertinent example often cited is the substantial stock sale by OpenAI employees in October 2025. This event, which saw over 600 current and former employees sell vested shares valued at approximately $6.6 billion, was conducted through a board-authorized tender offer. Institutional buyers such as Thrive Capital, SoftBank, Dragoneer, and T. Rowe Price participated in this transaction, with individual employee sales capped at $30 million.
The key distinction in this instance is that OpenAI itself organized, disclosed, and approved every single transfer. This authorized secondary sale, where the company maintains control over who is buying and formally signs off on each transfer, remains legal and is precisely what both companies are seeking to protect. The current crackdown targets transactions that circumvent this established process, including the proliferation of layered SPVs, tokenized wrappers, and listings on platforms without the company’s explicit consent.
Robinhood’s Fund and the Question of Consent
The situation also brings into focus recent investment activities by entities like the Robinhood Ventures Fund I. In April 2026, Robinhood announced its purchase of $75 million in OpenAI common stock, aiming to provide retail investors with exposure through a closed-end fund listed on the NYSE. While this vehicle represents a more regulated wrapper compared to a direct SPV pitch, Robinhood’s own product disclosures acknowledge that the fund obtains exposure "either through a direct investment in a company or via one or more special purpose vehicles."
As of Tuesday’s policy updates, there has been no public confirmation from OpenAI that it explicitly approved the April 17 transfer to the Robinhood Ventures Fund. This underscores a critical point: the validity of any transfer hinges not on whether the platform is regulated, but on whether the company has provided written consent for that specific transaction. The history between Robinhood and OpenAI includes a previous dispute over unauthorized tokenized OpenAI stock that Robinhood airdropped to European users. The lack of confirmed written consent for the recent $75 million purchase means it, too, could fall under the purview of the new voiding policies.
The Underlying Economic Drivers
The intense demand fueling this complex secondary market is understandable when examining the financial performance of these AI powerhouses. Anthropic, for example, has experienced explosive revenue growth, with its annualized revenue reportedly jumping from $9 billion at the end of 2025 to $30 billion by April 2026, a staggering 233% increase in a single quarter. This surge is largely attributed to the success of its Claude Code product, coupled with a significant commitment from Amazon to invest up to $25 billion in the company. At such remarkable growth rates, investors who are unable to gain access through official primary channels will inevitably continue to seek alternative routes.
Tuesday’s policy updates from Anthropic and OpenAI represent a decisive effort to close these "side doors" and regain control over their equity. Anthropic’s publication of a specific blocklist further emphasizes its proactive approach in identifying and neutralizing unauthorized trading activities. The implications for the secondary market are profound, potentially leading to greater scrutiny of all transactions involving private tech company shares and a renewed focus on official, board-approved channels for investment. The era of loosely structured and unverified private equity trading for these high-profile companies appears to be drawing to a close.
