Helion Secures $465M Funding to Build Fusion Power Plant for Microsoft

Helion, a fusion startup supported by Sam Altman, announced a new financing round. The company raised $465 million in fresh capital. The funding will be directed toward building a fusion power plant for Microsoft. Helion plans to use the investment to advance its reactor technology. A fusion reactor prototype from Helion glows purple. The purple glow is a visual characteristic of the operating reactor. Delivering a power plant to Microsoft could showcase commercial fusion energy. The project underscores growing interest in clean, high‑density power sources.