Sam Altman, OpenAI's CEO, is expected to testify this week in a federal courtroom in Oakland, California, in what may be the final stage of Elon Musk's lawsuit against the AI company. The trial has exposed internal emails, private journal entries, and strategic decisions that shaped one of the world's most valuable AI organizations. Altman's testimony comes after Microsoft CEO Satya Nadella took the stand to explain his company's role in OpenAI's transformation from a nonprofit research lab into a for-profit powerhouse now valued at over $850 billion.

What Is Elon Musk Actually Suing OpenAI For?

Musk co-founded OpenAI in 2015 as a nonprofit research organization dedicated to developing artificial general intelligence (AGI), a theoretical AI system that could match or exceed human intelligence across all domains. He left the organization in 2018 and has since become increasingly critical of its direction. In his lawsuit, Musk accuses OpenAI's leadership, particularly Altman, of betraying the company's original nonprofit mission by converting it into what is now one of the most valuable private companies in artificial intelligence.

Musk's core argument is straightforward: he donated $38 million to a nonprofit foundation and lent his name to a humanitarian mission, only to watch the people running it transform it into a money machine for themselves. He is calling for OpenAI to revert to its original nonprofit status, a move that would fundamentally reshape the company's position in the global AI race against competitors like Anthropic, Google, and China's Deepseek.

How Did Microsoft's Investment Change OpenAI's Direction?

Newly disclosed emails from January 2018 reveal that Microsoft executives were initially skeptical about OpenAI's potential. In one email, Microsoft CEO Satya Nadella expressed uncertainty about the company's research direction, writing: "Overall I can't tell what research they are doing and how if shared with us it could help us get ahead." However, Nadella also noted that Elon Musk was telling people OpenAI was "at verge of some big AGI breakthroughs".

Satya Nadella

The turning point came when OpenAI established a for-profit subsidiary to attract investment capital rather than relying solely on donations. In 2019, Microsoft finally invested $1 billion in the company. That initial investment has since grown to $13 billion, and Microsoft's stake is now valued at $228 billion, roughly 17 times the original investment. Musk's legal team is using these emails to argue that Microsoft knew it was helping divert a nonprofit foundation from its original purpose and only opened its checkbook once profit became possible.

What Do Greg Brockman's Private Journal Entries Reveal?

Perhaps the most damaging evidence in the trial comes from OpenAI President Greg Brockman's private journal entries, which span roughly a decade of internal deliberations at the company. These entries, originally submitted as sealed evidence in October 2025 and publicly unsealed in January 2026, detail Brockman's thinking about transitioning OpenAI from a nonprofit to a for-profit entity.

The journal entries include estimates of a pathway to $1 billion in personal net worth amid a $30 billion company valuation. One notable entry addresses Elon Musk's departure from OpenAI, suggesting that his exit was perceived internally as a morale hit, partly because of concerns about his pursuit of artificial general intelligence. Musk's legal team has seized on these entries to portray Brockman as a calculating opportunist who prioritized personal wealth over the company's founding mission.

Brockman also told lawyers that Musk physically threatened him in 2017 after Musk was refused absolute control of OpenAI, adding another layer of tension to the relationship between the two founders.

Key Evidence Expected at Trial

• Microsoft Emails: Correspondence from January 2018 showing Microsoft executives' initial skepticism about OpenAI's research direction and their decision to invest only after profit became possible.
• Journal Entries: Greg Brockman's decade-long diary detailing internal debates about transitioning from nonprofit to for-profit status and personal wealth calculations.
• AI Prompt Logs: All internal AI prompts used by OpenAI executives are logged and can be accessed during litigation, potentially revealing strategic discussions and decision-making processes.
• Founding Documents: Original nonprofit charter and mission statements that Musk's legal team argues were abandoned in pursuit of profit.

What Is OpenAI's Defense?

OpenAI counters that Musk left voluntarily after failing to seize majority control of the organization and has since become the company's direct competitor through his own AI venture, xAI. The company argues that the capped-profit structure it adopted was necessary to attract the investment capital required to compete in the AI arms race. Without the ability to offer equity stakes and profit-sharing arrangements, OpenAI contends it could not have raised the billions of dollars needed to develop ChatGPT and compete with well-funded rivals.

OpenAI also points out that Musk has recently announced a major partnership with Anthropic, OpenAI's top rival, to allow Anthropic to use computing capacity at SpaceX's largest data center, suggesting that Musk's motivations may be competitive rather than purely principled.

What Happens Next?

An advisory jury is expected to reach a verdict on any actual wrongdoing by the week of May 18. Judge Yvonne Gonzalez Rogers will then make the final ruling on both liability and remedies after hearing the jury's opinion. She has indicated she will likely follow the jury's advice.

The stakes are extraordinarily high. If Gonzalez Rogers ultimately sides with Musk, OpenAI's planned initial public offering (IPO) could be jeopardized. A forced conversion back to nonprofit status would also fundamentally alter the company's ability to raise capital and compete in the global AI market. For the broader tech industry, the trial serves as a cautionary tale about corporate governance, mission drift, and the discovery process in high-stakes litigation, where every Slack message, journal entry, and AI prompt log becomes potential evidence.