Musk’s $79–$134B Claim against OpenAI and Microsoft Relies on Contested ‘Made-Up’ Math

Musk wants up to $134 billion. The math behind it is already under fire.

Elon Musk took a dramatic step in his lawsuit against OpenAI and its largest backer, Microsoft, filing a notice on Friday that seeks between $79 billion and $134 billion in damages. The eye-popping numbers rest on a fresh expert report that attributes a large portion of OpenAI's current value to Musk's early involvement — an approach critics call speculative and legally shaky.

What Musk is asking for

The remedies notice confirms Musk's demand for damages in a very wide band: $79 billion on the low end and $134 billion at the high end. The complaint accuses OpenAI of abandoning its nonprofit mission and of "making a fool out of him" as an early investor. Microsoft is named as a co-defendant because of its role as OpenAI's largest backer.

The expert and the calculation

Musk retained a new expert witness, C. Paul Wazzan, who has not previously appeared for Musk in public filings. Wazzan concludes that Musk's early contributions generated between 50% and 75% of OpenAI's present value. To reach that conclusion he analyzed four factors:

• Musk's total financial contributions before he left OpenAI in 2018,
• Musk's proposed equity stake in OpenAI in 2017,
• Musk's current equity stake in his own company, xAI, and
• Musk's nonmonetary contributions to OpenAI, including time invested and reputational capital.

Taken together, the report maps those inputs into a damages range. Implicit in the math is an estimated current enterprise value for OpenAI in the roughly $158 billion to $179 billion range: if 50% of the company equals $79 billion, the full value implied is about $158 billion; if 75% equals $134 billion, the full value implied is about $179 billion.

Why the numbers are controversial

Several legal and valuation problems make the calculation vulnerable to attack:

• Attribution of value is inherently speculative. Quantifying how much of a thriving company's value came from one founder's early involvement is notoriously subjective. Valuation experts typically rely on market transactions, discounted cash flows, or comparable-company analysis — not retrospective percentage attribution to an individual founder.
• Comparing stakes across different entities is imperfect. Using Musk's current equity position in xAI as a comparator for what an interest in OpenAI would be worth conflates separate companies, different capital structures and different market conditions.
• Nonmonetary contributions are hard to price. Time, reputation and network effects matter, but converting them into a concrete dollar figure — and then asserting that those intangibles account for half or more of a multibillion-dollar company's value — invites skepticism.
• Legal theories must support the remedy. Even if Musk persuades a court that he contributed substantial value, he must also prove a legal right to damages in that amount — for example, that binding contractual, fiduciary or equitable obligations were breached and that the remedies claimed are available under applicable law.

How defendants are likely to respond

OpenAI and Microsoft are expected to attack both the factual basis and the methodology of the expert report. Typical defenses in disputes like this include challenging the admissibility of expert testimony, offering alternative valuations based on market evidence, and arguing that Musk had no enforceable ownership or compensation claim after his departure in 2018.

Microsoft's role as a co-defendant raises additional questions about vicarious liability and what obligations, if any, a corporate investor bears for actions taken by a separate nonprofit-turned-capped-profit entity.

What's next

The remedies notice is an opening salvo in what is likely to be a prolonged legal battle. Expect intensive discovery focused on early documents, communications about OpenAI's governance and capitalization, and expert dueling on valuation technique. Given the scale of the requested damages, both sides have strong incentives to press aggressively.

Why the tech world is watching

The case is about more than money. It raises deeper questions about how research nonprofits transform into funding-hungry commercial entities, how founders' early roles are recognized or rewarded, and what protections — if any — early donors or participants have after governance and capital structures change.

Bottom line: Musk's $79–$134 billion claim has grabbed headlines for its size and the boldness of its underlying math. But turning that headline number into a court-awarded judgment will require convincing a judge or jury that the new expert's attribution method is reliable, that Musk has enforceable legal rights, and that the law supports the extraordinary remedies sought. Those are high bars to clear.