Fusion power has shed its reputation as a perpetual pipe dream. Once dismissed as a technology forever a decade away, it now commands serious capital from investors betting on its potential to unlock near-limitless, clean energy. The shift from scientific curiosity to credible venture-backed enterprise is driven by three critical technological leaps: more powerful computing chips, sophisticated artificial intelligence, and the advent of high-temperature superconducting magnets. These tools enable advanced reactor simulations, refined control systems, and novel magnetic confinement designs that bring commercial viability within reach.
A pivotal moment arrived in late 2022 when researchers at a U.S. Department of Energy laboratory achieved scientific breakeven—a controlled fusion reaction that yielded more energy than the lasers delivered to the fuel pellet. While still far from the commercial breakeven needed for a power plant, this milestone validated the core physics and injected fresh momentum into the private sector. Today, a cohort of well-funded startups is racing to translate that science into market-ready reactors. Here is every fusion company that has raised over $100 million, detailing their designs, capital, and timelines.
Commonwealth Fusion Systems: The $3 Billion Behemoth
Commonwealth Fusion Systems (CFS) has secured roughly one-third of all private capital invested in fusion to date. Its latest funding round in August added $863 million, pushing total investment close to $3 billion. This Series B2 followed a $1.8 billion Series B four years prior, cementing its position as the sector’s best-funded player.
The Massachusetts-based startup is constructing Sparc, a first-of-a-kind tokamak reactor designed to produce power at “commercially relevant” levels. The D-shaped, doughnut-like chamber is wound with high-temperature superconducting tape to generate powerful magnetic fields that contain and compress superheated plasma. Heat from the reaction drives a steam turbine. CFS, which collaborates closely with MIT, expects Sparc to be operational by late 2026 or early 2027.
Later this decade, the company plans to break ground on Arc, a commercial plant near Richmond, Virginia, slated to generate 400 megawatts. Google has already committed to purchasing half its output. Backers include Breakthrough Energy Ventures, The Engine, and Bill Gates.
TAE Technologies: The $6 Billion Merger Play
Founded in 1998 as Tri Alpha Energy, TAE Technologies employs a field-reversed configuration with a twist: after plasma shots collide, particle beams bombard the plasma to maintain a stable, cigar-shaped spin. This enhances stability, allowing more time for fusion and heat extraction.
In December 2025, TAE announced an all-stock merger with Trump Media & Technology Group, valuing the combined entity at $6 billion. The deal includes $200 million upfront plus another $100 million upon SEC filing. CEO Michl Binderbauer will serve as co-CEO alongside Devin Nunes. Prior to the merger, TAE had raised $1.79 billion, including a $150 million round in June from investors like Google and Chevron.
Helion: Microsoft’s 2028 Power Partner
Helion boasts the most aggressive timeline, aiming to generate electricity by 2028 with Microsoft as its first customer. The Everett, Washington-based company uses a field-reversed configuration where plasma doughnuts collide at over 1 million mph. Fusion boosts the plasma’s magnetic field, inducing a current harvested directly from the reactor.
In January 2025, Helion raised $425 million around the time it activated its Polaris prototype. Total funding stands at $1.03 billion from backers including Sam Altman, Reid Hoffman, and Peter Thiel’s Mithril Capital.
Pacific Fusion: The $900 Million Series A
Pacific Fusion emerged with a staggering $900 million Series A. It pursues inertial confinement using coordinated electromagnetic pulses from 156 impedance-matched Marx generators to compress fuel, rather than lasers. CEO Eric Lander, who led the Human Genome Project, oversees milestone-based tranche payments from investors, a structure common in biotech.
Shine Technologies: The Pragmatic Pathfinder
Shine Technologies takes a cautious approach, focusing on neutron testing, medical isotopes, and radioactive waste recycling while deferring reactor design. It has raised $1 billion, including a $240 million round in February led by NantWorks. Other investors include Koch Disruptive Technologies and the Wisconsin Alumni Research Foundation.
General Fusion: The Veteran’s Struggle
Founded in 2002, General Fusion has raised over $600 million for its magnetized target fusion (MTF) approach, where pistons compress a liquid metal wall to ignite plasma. Investors include Jeff Bezos and Temasek. The company hit a cash crunch in spring 2025, laying off 25% of staff after a key milestone. An August pay-to-play round injected $22 million, followed by $51.1 million in SAFE notes. In January, it announced a reverse merger with a SPAC that could bring $335 million more.
Inertia Enterprises: The NIF Alumni’s Venture
Inertia Enterprises emerged from stealth in February with $450 million in Series A funding. Its founding team includes Annie Kritcher, chief scientist of the National Ignition Facility experiment that achieved breakeven. The startup plans an inertial confinement design using lasers, backed by Bessemer Venture Partners and GV.
Tokamak Energy: The Compact Tokamak
Tokamak Energy squeezes the traditional tokamak into a spherical shape, using high-temperature REBCO magnets to reduce costs. Its ST40 prototype reached 100 million degrees Celsius in 2022. A $125 million round in November 2024 brought total funding to $336 million. Investors include In-Q-Tel and Capri-Sun founder Hans-Peter Wild.
Zap Energy: The Z-Pinch Pioneer
Zap Energy forgoes magnets and lasers, using an electric current to zap plasma, generating a self-confining magnetic field. The Everett, Washington-based company has raised $327 million from backers like Breakthrough Energy Ventures and Chevron.
Type One Energy: The Stellarator on a Coal Site
Type One Energy plans a 350-megawatt stellarator reactor on a retired TVA coal plant by the mid-2030s. It aims to sell technology for others to build and operate. The company has raised $269 million, including an $87 million equity round ahead of a $250 million Series B.
Proxima Fusion: The Stellarator’s €185 Million Bet
Proxima Fusion attracted a €130 million Series A, totaling over €185 million, to advance stellarator technology, which twists magnets to stabilize plasma. Backers include Balderton Capital and Cherry Ventures.
Kyoto Fusioneering: The Balance-of-Plant Specialist
Kyoto Fusioneering bets on supplying components like gyrotrons and heat extraction systems, having raised $191 million from investors including Mitsubishi and Sumitomo.
Marvel Fusion: The Laser and Silicon Play
Marvel Fusion uses lasers to compress silicon nanostructure targets, leveraging semiconductor manufacturing. The Munich-based startup has raised $162 million and plans a demonstration facility with Colorado State University by 2027.
First Light Fusion: The Projectile Approach
First Light Fusion fires a projectile using a two-stage gun to compress fuel, diverging from laser-based inertial confinement. In March 2025, it pivoted from building a power plant to licensing its technology. The U.K. company has raised $108 million from investors like Invesco and Tencent.
Xcimer: The Laser Powerhouse
Xcimer aims for a 10-megajoule laser system, five times more powerful than NIF’s, with molten salt walls for heat absorption. Founded in 2022, it has raised $100 million from Breakthrough Energy Ventures and Lowercarbon Capital.
The fusion landscape is no longer speculative. With over a dozen startups each backed by $100 million or more, the race to commercialize star power is fully funded and fiercely competitive. The coming years will test whether these capital-intensive bets can deliver on the promise of limitless energy.
