Elon Musk is suing OpenAI and Microsoft for up to $134 billion, claiming the companies earned "wrongful gains" from his early support, according to a court filing Friday.
The lawsuit centers on Musk's contributions when OpenAI was founded in 2015 and his claim that both companies benefited unfairly from his involvement.
Musk's filing estimates that OpenAI gained between $65.5 billion and $109.4 billion, while Microsoft earned between $13.3 billion and $25.1 billion, thanks to his initial seed funding and guidance, Engadget reported.
Musk contributed roughly $38 million, which amounted to about 60% of OpenAI's early funding. He also helped recruit key staff, connect the founders with business contacts, and lend credibility to the fledgling project.
"Without Elon Musk, there'd be no OpenAI. He provided the bulk of the seed funding, lent his reputation, and taught them all he knows about scaling a business," Musk's lead lawyer, Steven Molo, said in a statement to Reuters.
Musk left OpenAI in 2018 and now runs xAI, which operates a competing chatbot named Grok.
The lawsuit claims OpenAI violated its original non-profit mission when it restructured as a for-profit entity, giving Microsoft and other investors an unfair advantage.
Elon Musk seeks up to $134B from OpenAI and Microsoft over ‘wrongful gains’ from his initial contributions https://t.co/bz0eD31Xjv pic.twitter.com/Z5PeS7jVUi
— New York Post (@nypost) January 18, 2026
Elon Musk May Seek Punitive Damages
OpenAI dismissed the claim as an "unserious demand" and accused Musk of conducting a "harassment campaign" against the AI company.
Microsoft did not immediately comment on the filing. According to the NYPost, both companies challenged Musk's damages claims in a separate court submission, arguing that the expert valuations used in his filing are "made up" and "unverifiable."
A judge in Oakland, California, recently ruled that a jury will hear the trial, expected to begin in April. Musk's filing also notes that he may pursue punitive damages or other penalties, including a potential injunction, if the court finds the companies liable.
Financial economist C. Paul Wazzan, Musk's expert witness, calculated the monetary estimates, concluding that OpenAI and Microsoft's "wrongful gains" far exceed Musk's original contributions.
"Just as an early investor in a startup may realize gains many times greater than the 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," the filing said.
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