Helion Energy has closed its Series G round at $465 million, pushing its post-money valuation to $15.5 billion — nearly three times the $5.43 billion reached in the Series F of January 2025. Among its long-standing shareholders is Nucor, the largest steel producer in the United States, which reported a non-cash pre-tax gain in its Q2 2026 results directly tied to the increased value of its stake in Helion.
The round was led by Thrive Capital, with new investors including Alta Park Capital, Lux Capital, Peak XV Partners, and Bill Ford, Executive Chairman of Ford Motor Company. Existing backers also participated: Capricorn Technology Impact Funds, Lightspeed Venture Partners, Mithril Capital, SoftBank Vision Fund 2, and Dustin Moskovitz’s Good Ventures Foundation. Total capital raised by Helion since its founding now exceeds $1.5 billion. The Everett, Washington-based startup is now the highest-valued private fusion company in the world.
The proceeds will be used to accelerate commercial deployment, expand manufacturing capacity, and meet rapidly growing energy demand. Helion is building Orion, its first commercial fusion plant, in Malaga, Washington State. The company has already signed a binding agreement to supply Microsoft with 50 megawatts of power by 2028 — a deal without precedent in the private fusion sector. In parallel, Helion is completing a facility for Omega capacitor production in Everett. Its seventh-generation prototype, Polaris, has recently achieved a series of technical milestones validated by five peer-reviewed scientific papers.
For Nucor, the investment in Helion is part of a long-term energy diversification strategy. Steel is an energy-intensive industry, and the prospect of accessing fusion-generated power — clean and theoretically unlimited — represents a concrete industrial objective. The revaluation of its stake recorded in Q2 2026 shows that the financial bet is already paying off in the near term, regardless of the technical timeline for the commercial plant.
With $1.5 billion raised in total and a supply agreement with a hyperscaler like Microsoft, Helion stands apart from its peers in the private fusion space — not just by valuation, but by the tangibility of its commercial commitments. If the Orion plant meets its announced deadlines, the company could become the first operator in the world to sell fusion-generated electricity at commercial scale. A milestone that would reshape the global energy equation — and turn Nucor’s investment, already profitable on paper, into something far more significant.
