Elon Musk has asked a US court to order OpenAI and Microsoft to pay him damages of up to $134 billion, arguing the companies benefited from what he calls “wrongful gains” linked to his early backing of OpenAI.

What Musk is Demanding

In court papers filed on Friday, Musk’s legal team said he was allegedly defrauded of the $38 million in seed money he donated to OpenAI in 2015. The filing argues he is now entitled to a share of the company’s current valuation of $500 billion.

The document sets out a range for the gains Musk says should be repaid. It claims OpenAI gained between $65.5 billion and $109.4 billion from that early funding. It also claims Microsoft gained between $13.3 billion and $25.1 billion.

Why He Says OpenAI “Would Not Exist” Without Him

Musk’s lead trial lawyer, Steven Molo, said Musk provided the bulk of the seed funding, lent his reputation and shared what he knows about scaling a business. The court filing cites estimates by an expert witness, financial economist C. Paul Wazzan.

Musk helped co-found OpenAI in 2015 and invested about $45 million in total, according to the same report. He later left the board in 2018 after strategic disagreements with CEO Sam Altman.

How OpenAI and Microsoft are Pushing Back

OpenAI has rejected the damages demand, calling it “baseless” and part of a “harassment” campaign. Microsoft did not comment on the compensation issue.

OpenAI and Microsoft also filed separately asking the judge to exclude Wazzan’s analysis, describing it as “made up” and “unverifiable”.

The Wider OpenAI Valuation Fight

The dispute is playing out as OpenAI’s value has surged. The report says OpenAI reached a $500 billion valuation in October after current and former employees sold roughly $6.6 billion in shares to a consortium of investors.