Proxima Fusion joins the club of well-funded nuclear contenders with €130M Series A

Commercial nuclear fusion power isn’t a reality yet. But venture capital is flowing into startups that promise that clean, safe, and virtually limitless energy is no longer just a distant dream.

Most fusion companies that have raised over $100 million are based in the United States. Not Proxima Fusion, a German startup that has just secured a €130 million Series A round of funding (approximately $148 million) led by Balderton Capital and Cherry Ventures.

This brings Proxima’s public and private funding to date over €185 million ($200 million), increasing its chances to be one of Europe’s top contenders in this race for an alternative to fission, one which does not depend on uranium or other imported fissile materials used in current nuclear reactors.

The pursuit isn’t solely for scientific prestige; it is deeply intertwined with energy security. “Wait for the early 2030s and you will see fusion giants in each geopolitical block,” Proxima’s CEO and co-founder Francesco Sciortino predicted in an interview with TechCrunch.

Until now, Proxima didn’t have the means to become such a giant; its April 2024 seed round was only €20 million ($21.7 million). Since then Proxima published its plans for a working fusion power plant in a peer-reviewed journal.

The paper made the case for stellarators, a type of reactor that uses magnetic fields to confine hot plasma into a ring long enough for fusion to occur. Unlike their main alternative, tokamaks, stellarators’ twisted rings don’t require a plasma current, making them more stable. Building upon its proximity to the world’s largest stellarator, Germany’s Wendelstein 7-X, Proxima came up with its own Stellaris design, a significant milestone detailed in the paper.

The hefty new funding was partly a reflection of reaching this milestone in half the time it had originally told investors, Sciortino said. With an oversubscribed round, the company had its pick. “Now we have the right kind of partners not just for this stage, but to finance us in the next stage.”

Both funds that co-led the round could follow on. Balderton raised $1.3 billion in 2024 for its Early Stage Fund IX and its Growth Fund II. As for Cherry, it closed its latest fund at $500 million in February 2025, to be split between early-stage and follow-ons at Series B and beyond.

Sciortino estimates that it will need venture capital as an investment category “to bring [Proxima] to 2031, give or take.” After that point, the company expects to seek other forms of capital. But before then, it will need the capital to meet big milestones, including a critical hardware demonstration scheduled for 2027. In his view, the funding was made possible by the understanding that “that this is not an infinitely long journey for our current investors.”

By the rules of venture capital, investors may be less convinced that fusion will happen on that timeline, but they are willing to bet. Ian Hogarth, a partner at founders-led fund Plural, has now invested in Proxima three times, and calls it a “big shot.”

A nuclear fusion future is particularly appealing for the Old Continent. “Proxima represents an opportunity to decarbonize and provide a stable baseload for all the downstream energy needs the world has, and for Europe to play a global leadership role in driving the energy transition,” Hogarth told TechCrunch.

Proxima’s cap table is once again very European, with participants in the round including Bayern Kapital, Club degli Investitori, DeepTech & Climate Fonds (DTCF), Elaia, HTGF, Leitmotif, Lightspeed, OMNES Capital, and UVC Partners.

“We consider Proxima to be thoroughly European and not just German,” Sciortino said. Proxima has its headquarters and lab in Munich, where it spun off from the Max Planck Institute of Plasma Physics (IPP). But it also has teams at Switzerland’s Paul Scherrer Institute and at the Culham Centre for Fusion Energy, the U.K.’s national laboratory for fusion research near Oxford.

Sciortino himself, a physicist by background, is originally from Italy, but worked on fusion research in the U.K., Switzerland, and then at MIT in the U.S. There were several reasons for him to move back to Europe, but one of them speaks to a sentiment echoed by investors: “I’m a fairly proud European, and always wanted to think that there is a future on this continent that somebody has to build.”