Explained: Why Elon Musk and Sam Altman are facing off in trial over OpenAI

By Pascale Davies Published on 27/04/2026 - 14:37 GMT+2 Share Comments Share Facebook Twitter Flipboard Send Reddit Linkedin Messenger Telegram VK Bluesky Threads Whatsapp

The trial will see Elon Musk face off against OpenAI CEO Sam Altman over allegations that the AI company abandoned its nonprofit roots in favour of profit — with Microsoft also named in the suit.

Technology titans Elon Musk and Sam Altman will face off in a high-stakes trial on Monday in the culmination of a years-long battle.

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Billionaire Musk, an early investor in the artificial intelligence company, is suing OpenAI’s CEO, Altman, its president Greg Brockman, and Microsoft for allegedly betraying an agreement about keeping OpenAI as a nonprofit that benefits humanity.

Musk alleges he was misled when Altman transformed the company from a nonprofit into a for-profit enterprise. The company now has a valuation of almost $1 trillion and is expected to go public.

Here’s everything to know about the trial.

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The trial will happen at the US District Court for the Northern District of California in Oakland, with Judge Yvonne Gonzalez Rogers.

The court hearing begins on Monday and is expected to last around two to three weeks.

The witness stand is expected to gather Musk, Altman, and Microsoft CEO Satya Nadella.

What does Musk allege?

Altman, Musk, and other founders launched OpenAI in 2015 as a non-profit organisation.

Musk was the biggest individual financial backer of OpenAI in the beginning, contributing more than $44 million to the then-startup.

Musk left OpenAI’s board in 2018 after clashing with Altman. A year earlier, he reportedly made a failed bid to get more control over the company.

In 2022, OpenAI launched ChatGPT and grew to become one of the most valuable and important AI companies with major investment from Microsoft.

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Then in 2025, OpenAI restructured its main business to become a for-profit company.

Musk’s lawsuit was filed in 2024 and claims OpenAI had breached an agreement to make breakthroughs in AI “freely available to the public” by forming a multibillion-dollar alliance with Microsoft, which invested $13 billion (€12 billion) into the company.

“OpenAI, Inc has been transformed into a closed-source de facto subsidiary of the largest technology company in the world: Microsoft,” Musk’s lawsuit alleges.

The Tesla boss, who also has his own generative AI company xAI, says this constitutes a breach of a contract.

What does OpenAI say?

OpenAI released a trove of emails in 2024 that show Musk supported its plans to create a for-profit company, which he wanted to be the head of, have board control, and merge it with Tesla.

OpenAI has always denied Musk’s allegations, saying that he agreed in 2017 that establishing a for-profit entity would be necessary.

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