Fusion Startup Helion Nearly Triples Valuation to $15.5 Billion in Thrive-led Round

Helion Energy, a nuclear fusion startup backed by OpenAI’s Sam Altman, still has to prove it can produce electricity to serve data centers and other customers. But investors seem confident it can deliver. The Everett, Wash.–based company said it has raised $465 million in a funding round led by Thrive Capital, the investment firm founded by Josh Kushner, a big backer of OpenAI. Helion’s valuation after the investment was $15.5 billion, nearly triple the company’s $5.43 billion valuation...