Massachusetts startup Commonwealth Fusion Systems (CFS) has secured $863 million in funding from a wide range of investors, including Google, Nvidia, Breakthrough Energy Ventures, and other global investors. Total funding now reaches nearly $3 billion, making CFS the most-funded fusion startup in the world.

CEO Bob Mumgaard said, “This capital isn’t just about exploring fusion—it’s about turning it into a commercial industrial enterprise.” The company is currently building Sparc, a tokamak prototype reactor that aims to begin operations next year. Sparc’s goal is scientific breakeven in 2027, producing more energy than is required to ignite it.

While Sparc will not deliver power to the grid, it is essential for validating CFS’s technology, estimating costs, and training teams for future projects. Assuming Sparc succeeds, CFS plans to construct Arc, its first commercial-scale fusion plant in Virginia, starting in 2027–2028. The diverse investor group will play a key role in supporting the company’s supply chain, partnerships, and industrial fusion ambitions.