Helion, a nuclear fusion startup, raised $500 million in Series E funding at a $3 billion post-money valuation. Investors include Sam Altman, Dustin Moskovitz, Reid Hoffman, Mithril Capital and Capricorn Investment Group.

Helion is developing the Fusion Engine, a near term and low cost solution for clean, safe energy. The Fusion Engine's patented reactor technology is based on award winning and peer reviewed research. Recent technology breakthroughs enable clean fusion energy now.