Elon Musk has filed a sweeping claim in US federal court seeking as much as $134 billion, alleging that OpenAI and Microsoft were unjustly enriched by his early contributions to the research lab he helped found. The complaint portrays Musk not merely as an early donor but as an architect of OpenAI’s initial organisation, recruiting and strategy, and argues that later commercialisation amounted to a legal and moral expropriation of his original inputs.
Musk’s filings say he provided roughly $38 million at OpenAI’s founding — about 60% of the seed funding — and that his non-financial contributions conferred substantial economic value on the venture. An expert witness retained by Musk, the financial economist C. Paul Wazzan, places the economic benefit arising from Musk’s combined contributions to OpenAI between $65.5 billion and $109.4 billion, and assesses Microsoft’s gains from its close partnership with OpenAI at between $13.3 billion and $25.1 billion.
OpenAI and Microsoft have responded forcefully. OpenAI dismissed the suit as baseless and characterised it as harassment, while Microsoft denied any role in inducing OpenAI to breach founding commitments. In a joint filing, the two defendants asked the court to exclude the expert’s testimony, calling his valuation model unverified and unprecedented and warning that Musk’s theory would amount to an extraordinary and legally unjustified transfer of funds.
At the heart of the dispute is a legal and governance question with industry-wide resonance: did OpenAI’s original non-profit mission create enforceable rights for founders and early supporters, and did the lab’s later conversion to a capped-profit structure — accompanied by major commercial agreements — breach those obligations? Musk frames the transition to commercial partnerships and a profit-oriented structure as a departure from a founding promise to develop AI for the benefit of all humanity. OpenAI counters that restructuring was necessary for sustainability and that no legally binding promise prevented it from seeking revenue or private capital.
The lawsuit lands as OpenAI begins to test advertising in ChatGPT — a strategic pivot toward conventional monetisation as the company seeks to cover massive infrastructure and operating costs. OpenAI says it will show ads only to adult free users in the US, place ads clearly at the bottom of chatbot responses, exclude ads from sensitive topics, and will not sell user data. The company has also launched lower-cost subscription tiers that will carry advertising, while premium subscriptions will remain ad-free.
Beyond the headline dollar figures, the case could set a precedent for how founder contributions are valued when mission-driven organisations pivot to commercial models. It will also test the enforceability of informal or ideological commitments in the face of formal corporate restructurings and outside investment. For technology companies racing to scale compute-heavy AI services, the case highlights governance risks that can materialise as firms transition from research projects to revenue-generating enterprises.
Even if the courts reject Musk’s claims, the litigation is likely to reverberate through Silicon Valley and among policymakers. Investors, partners and regulators will scrutinise governance documents, founder agreements and the terms under which nonprofits convert or spin out commercial entities. At the same time, OpenAI’s ad tests underscore the financial pressures that prompted its corporate evolution: monetisation choices that preserve user trust will be crucial if the company is to meet its expansive revenue and infrastructure commitments without alienating users or attracting regulatory backlash.