Helion Energy Raises $465M Series G at $15.5B Valuation — Nearly Triples from Prior Round

Helion Energy announced on June 4, 2026 the closing of a $465 million Series G round led by Thrive Capital, bringing the company's valuation to $15.5 billion — a nearly 3× increase from its January 2025 valuation of $5.43 billion. New investors include Alta Park Capital, Anti Fund, BoxGroup, Lux Capital, Peak XV Partners, and Bill Ford (Ford Motor Company Executive Chairman); returning investors include Capricorn Technology Impact Funds, Lightspeed Venture Partners, Mithril Capital, SoftBank Vision Fund 2, and Sam Altman (through Good Ventures Foundation and personal capacity). The raise brings Helion's total capital to $1.5 billion. Funds will accelerate construction of Orion, Helion's first fusion power plant being built in Malaga, Washington, and expand U.S. manufacturing capacity for commercial-scale deployment. Helion's Polaris prototype became the first privately-funded fusion device to operate with deuterium-tritium fuel and achieved plasma temperatures of 150 million °C in February 2026. CEO David Kirtley stated: 'Fusion is no longer a future idea, but a path to clean, reliable, affordable always-on electricity at scale.' Helion maintains its target to deliver electricity to Microsoft's data centers by 2028 under a binding power purchase agreement. Thrive Capital partner Josh Kushner said: 'Helion has the technical ambition, pace of execution, and commercial orientation to define a new category of energy.'