For years, construction workers at Helion Energy’s factory in Everett, Washington, have been developing the Polaris prototype, a device that mimics how the sun produces electricity. The device became the first private fusion firm to run on deuterium-tritium fuel when it reached 150 million degrees Celsius in February 2026. Net-positive energy has not yet been generated by it.
Commercial operation is still scheduled for 2028. Real scientific advancement, genuine skepticism from physicists who have seen the fusion timeline recede for decades, and an investor named Sam Altman who has wagered a sizeable portion of his personal wealth on the outcome while simultaneously managing the business that could grow to be Helion’s biggest client are all present in this productive tension.
According to financial statements made during the Musk v. Altman trial in Oakland, Altman owns around one-third of Helion, which is estimated to be worth between $1.65 and $1.7 billion as of December 2025. Over 80% of his $2 billion reported portfolio, which is spread among nine private companies, comes from Helion alone.
The investment trail includes the $500 million Series E round that Altman led in 2021, a $425 million Series F round in January 2025 that brought in SoftBank Vision Fund 2, Mithril Capital, and Lightspeed Venture Partners and valued the company at $5.4 billion, and the June 2026 funding round that is detailed in the reference material. No commercial income as of yet. However, the value continues to increase.
The supply agreement between Helion and OpenAI, where Altman is CEO, has garnered the greatest attention. In March 2026, Axios revealed that the companies were in the early stages of negotiations for a deal that would allow Helion to provide OpenAI with up to 5 gigawatts of power by 2030 and possibly 50 gigawatts by 2035. This amount would require Helion to construct and install more than 8,000 separate reactors within ten years. Depending on who you ask, the size of that forecast is either improbable or visionary, and there is no agreement among scientists on the subject.
The governance issue, in which Altman was concurrently chairing Helion’s board and spearheading the company’s negotiations to become Helion’s largest client, was what led to instant agreement. He has often declared that he recuses himself from any merger negotiations between the two firms, and he resigned from the board in March 2026 to allow the talks to continue. In the Oakland trial, Elon Musk’s legal team contended that the recusal was inadequate.
Another layer is added by Microsoft’s involvement. The largest investor in OpenAI, the software behemoth, has already signed a power purchase agreement with Helion, promising to acquire 50 megawatts of electricity from the first commercial plant beginning in 2028. This is the first such arrangement for fusion energy anywhere in the world.
Although it’s important to note that Microsoft’s agreement was designed with a financial penalty if Helion fails to deliver, indicating that the energy giant’s confidence is conditional rather than unconditional, that contract offers some external validation of the business notion.
Observing the congressional investigations and trial testimony surrounding this investment gives one the impression that, despite the fact that the answer is actually unclear, the question being raised is reasonable. Is Altman trying to boost the value of his own Helion share by taking advantage of OpenAI’s market position and energy requirements?
Or is he the exceptional tech CEO who saw an actual energy issue early on and invested his own money to find a solution, and the overlap results from working in related sectors at the same time? There is merit to both interpretations of the circumstances. Which one the courts and regulators will ultimately choose is still up in the air.
