Proxima Fusion has announced a €411 million funding round — approximately $468 million — bringing its valuation to €2.4 billion and making it the best-funded fusion company in Europe. The round was led by XTX Ventures and East X Ventures, with strategic participation from RWE and Google. Other investors include KfW Capital, SPRIND, Balderton Capital, Cherry Ventures, and DST Global Partners, with several returning backers reaffirming their confidence in the company.
Founded in Munich in 2023 as the first spin-out of the Max Planck Institute for Plasma Physics, Proxima Fusion has moved fast. The team — more than 150 physicists, engineers, and operators — is led by CEO Francesco Sciortino, who previously worked at the same institute as a European coordinator for tokamak research before pivoting to stellarators following results achieved with the Wendelstein 7-X. The other co-founders come from MIT, Harvard, SpaceX, Tesla, and McLaren — a depth of expertise that underpins the entire venture.
The company’s roadmap has three milestones. By 2027, Proxima will complete the Stellarator Model Coil, a demonstrator magnet designed to validate the use of high-temperature superconductors in stellarator magnets — a technology developed in collaboration with the Paul Scherrer Institute in Switzerland. This will be followed by construction of the Alpha demonstrator, scheduled to begin in early 2027, with the target of achieving net energy gain by 2031. Alpha will be built near Garching, home of the Max Planck IPP. The ultimate goal is Stellaris, the world’s first commercial stellarator, to be built on the site of the decommissioned Gundremmingen fission plant in Bavaria, with RWE as the industrial partner.
The quasi-isodynamic stellarator — the type of machine Proxima is developing — has a key advantage over the tokamak design used by ITER: net toroidal currents in the plasma cancel out to zero, enabling continuous, stable operation. This makes it, at least in principle, better suited to commercial electricity generation. The Stellaris concept, published in a peer-reviewed paper in February 2025, has been described as the world’s first fully integrated design for a fusion power plant engineered for reliable, steady-state operation. In July 2025, the German federal government had already designated fusion as one of the country’s six critical technologies of the future, committing more than €1 billion to research through 2028.
With this latest round, Proxima has raised over €650 million in total. Google has also chosen to invest in U.S. rival Commonwealth Fusion Systems — a signal that major tech capital now treats fusion as a real market, not a distant hypothesis. RWE, for its part, committed €25 million just months after signing the agreement to host Stellaris at Gundremmingen, turning what was a memorandum of intent into a concrete financial stake. If Alpha demonstrates net energy gain by the early 2030s, the path to Europe’s first fusion power plant will be all but set in stone.
