Helion, a fusion energy company, announced a $425 million Series F investment round that will be used to scale commercialization efforts for the company's groundbreaking fusion technology. The oversubscribed and upsized round had participation from new investors, including Lightspeed Venture Partners, SoftBank Vision Fund 2, and a major university endowment, and existing investors including Sam Altman, Mithril Capital, Capricorn Investment Group, Dustin Moskovitz through Good Ventures Foundation, and Nucor.