Helion, a Washington-based fusion energy company, said on June 4 that it raised US$465 million in a series G round led by Thrive Capital.

The funding will expand US manufacturing capacity and support commercial deployment, valuing Helion at US$15.5 billion post-money.

The financing follows a US$425 million series F announced in January 2025, which valued Helion at US$5.425 billion post-money and brought its total funding to more than US$1 billion.

Helion has said Polaris, its seventh prototype, began operating in 2025 to demonstrate electricity production from fusion.

In February 2026, the company said Polaris reached 150 million degrees Celsius and demonstrated measurable deuterium-tritium fusion.

Helion also has a 50-megawatt agreement to supply Microsoft from its first fusion power plant by 2028.

Output is targeted at 50 megawatts or more after a one-year ramp-up. Helion said Orion, the company’s first plant, is under construction in Malaga, Washington.

🔗 Source: Helion