Musk seeking up to $134bn from OpenAI, Microsoft in "wrongful gains"

Elon Musk is seeking between $79 billion and $134 billion in damages from ChatGPT’s owner, OpenAI, and Microsoft, arguing that he’s entitled to “wrongful gains that OpenAI and Microsoft have earned”.

A court filing on Friday, cited by Bloomberg, provides calculations of Musk’s financial and non-monetary contributions by a financial economist expert witness, C. Paul Wazzan, saying that the tech mogul has a right to a portion of OpenAI’s current $500 billion valuation.

Specifically, the filing says Musk was defrauded of the $38 million in seed funding he provided to OpenAI in 2015. As a result, he now seeks between $65.5 billion and $109.43 billion from OpenAI, as well as between $13.3 billion and $25.06 billion from OpenAI's biggest partner, Microsoft.

“Just as an early investor in a startup company may realize gains many orders of magnitude greater than the investor’s initial investment, the wrongful gains that OpenAI and Microsoft have earned – and which Mr. Musk is now entitled to disgorge – are much larger than Mr. Musk’s initial contributions,” Musk lawyer Steven Molo wrote, according to Bloomberg.

Musk left OpenAI in 2018 and then began his legal campaign against the company in 2024, claiming that it abandoned its original plans of operating as a non-profit organization and misled him. In a public argument on X, Musk accused OpenAI CEO Sam Altman: “You stole a non-profit.”

Musk further argues that OpenAI now serves the interests of Microsoft, which holds approximately a 27% ownership share in the restructured OpenAI Group PBC.

While Microsoft declined to comment, OpenAI said in a statement that the move reflects Musk’s “ongoing pattern of harassment”.

“Mr Musk’s lawsuit continues to be baseless and a part of his ongoing pattern of harassment, and we look forward to demonstrating this at trial. This latest unserious demand is aimed solely at furthering this harassment campaign.”

OpenAI argues that Musk’s legal bid is meant to slow them down and benefit his own company, xAI.

A federal judge has rejected OpenAI’s and Microsoft’s attempts to dismiss the case and avoid a jury trial, which is currently scheduled to go ahead in late April 2026 in Oakland, California.