The trial, which opened on Tuesday 28 April, pits Musk against Sam Altman, Greg Brockman and OpenAI itself, according to reporting by the Guardian. It is expected to feature testimony from both billionaires and several of the most powerful executives in the technology industry. At its core, the dispute is not merely a feud between former co-founders; it is a test of whether founding commitments to public benefit can survive the gravitational pull of commercial capital.

OpenAI, co-founded by Musk, Altman and Brockman in 2015 as a non-profit artificial intelligence research laboratory, has grown into one of the most valuable private technology companies in the world. Recent funding rounds have reportedly valued the organisation at around $300bn, a sharp increase from roughly $29bn in early 2023. Microsoft has committed more than $13bn in cumulative investment, according to publicly reported figures.

What each side argued in opening statements

Musk's legal team told the jury that Altman, Brockman and OpenAI broke a foundational agreement to operate for the benefit of humanity when the organisation pivoted towards a for-profit structure, as reported by the Guardian. Musk, who left OpenAI's board in 2018, further alleges that his co-founders unjustly enriched themselves as the company raised billions of dollars and grew into what his lawyers described as an AI behemoth.

The lawsuit was originally filed in early 2024, voluntarily withdrawn, and then refiled later that year with additional claims, including allegations under the Racketeer Influenced and Corrupt Organizations Act (RICO). The RICO count was subsequently dismissed by the court, but breach-of-contract and unjust-enrichment claims survived and now form the backbone of the trial.

OpenAI's defence, as outlined in prior court filings, centres on the argument that no binding contract of the kind Musk describes ever existed, and that the organisation's structural evolution was a necessary response to the enormous capital requirements of frontier AI research. Altman has previously stated publicly that Musk was aware of and initially supportive of efforts to attract outside investment.

The governance question: non-profit origins, for-profit ambitions

The case exposes a tension that has become increasingly common in the technology sector: how organisations founded with explicit public-benefit missions navigate the transition to structures capable of absorbing billions in private capital.

OpenAI began life as a 501(c)(3) non-profit under US tax law. In 2019, it created a "capped-profit" subsidiary, OpenAI LP, designed to allow outside investment while theoretically preserving the non-profit's oversight role. The non-profit board retained nominal control, including the power to determine when the organisation's mission had been fulfilled.

That hybrid arrangement came under intense scrutiny in November 2023 when OpenAI's board briefly fired Altman as chief executive, only to reinstate him days later following pressure from investors and employees. The episode laid bare the structural contradictions of a governance model in which a non-profit board held authority over a commercial operation valued in the tens of billions.

More recently, OpenAI has proposed converting entirely to a for-profit public benefit corporation. That plan has drawn formal scrutiny from multiple US state attorneys general, who have questioned whether the conversion adequately protects the charitable assets originally dedicated to the non-profit's mission.

The trial jury will not rule on the conversion itself, but the evidence presented, particularly around the original founders' intentions and any documented agreements, could influence how regulators and courts assess the legitimacy of the restructuring.

What the trial means for AI-sector deal structures

The outcome carries significant implications for deal-making across the AI sector. Investors who have committed capital to OpenAI on the basis of its current or proposed corporate structure will be watching closely. A finding that enforceable commitments were made to maintain a non-profit model could, in principle, complicate similar hybrid arrangements at other AI laboratories.

Several prominent AI organisations, including Anthropic, were founded with governance structures explicitly designed to prioritise safety over profit maximisation. If the jury finds that OpenAI's founders made binding promises about corporate purpose, it could raise the cost of restructuring for any mission-driven AI company seeking to attract large-scale commercial investment.

Conversely, a verdict favouring OpenAI would likely be interpreted as confirmation that founding-era discussions and aspirational statements do not necessarily create enforceable obligations, potentially giving other organisations greater latitude to evolve their structures as capital needs change.

For venture capital and growth equity investors, the case underscores the importance of documenting governance arrangements with precision at the point of initial investment, rather than relying on informal understandings about corporate purpose.

Implications for UK operators with hybrid corporate models

The trial resonates beyond Silicon Valley. In the UK, hybrid models blending social purpose with commercial activity are well established. Community interest companies (CICs), charitable incorporated organisations with trading subsidiaries, and social enterprises operating as limited companies all occupy similar structural territory.

The UK government is currently developing its own AI governance framework, and the Musk v Altman proceedings arrive at a moment when policymakers are actively considering how corporate structure intersects with AI safety obligations. The Department for Science, Innovation and Technology published a consultation on AI regulation in 2024, and ministers have signalled an intention to introduce binding requirements for the most capable AI systems.

For UK founders and directors operating hybrid structures, the case offers a practical reminder. Founding documents, board minutes and early correspondence can all be used to establish the existence and scope of commitments to a stated mission. Where an organisation's purpose is enshrined in its articles of association or governing documents, any subsequent pivot towards a purely commercial model may face legal challenge from stakeholders, regulators or, as in this case, former co-founders.

The Charity Commission for England and Wales already exercises oversight of charitable assets and has the power to intervene where it believes assets are being diverted from their intended purpose. A high-profile US verdict reinforcing the enforceability of founding commitments could embolden similar scrutiny in the UK context.

Governance discipline as a competitive advantage

Rather than viewing governance constraints as obstacles to growth, UK scale-ups with social or public-benefit missions may find that clear, well-documented governance arrangements become a source of credibility with institutional investors, particularly those subject to environmental, social and governance (ESG) mandates.

The Musk v Altman trial, whatever its verdict, has already demonstrated that ambiguity in founding agreements creates risk. For operators building organisations intended to balance purpose with profit, the lesson is straightforward: define the terms early, document them thoroughly, and ensure that any structural evolution is conducted transparently and with proper legal authority.

The trial is expected to last several weeks. Both Musk and Altman are scheduled to testify.