Fusion startups race past $100M with real stakes

fusion startups – Fusion has shifted from punchline to boardroom priority. A wave of companies has now raised more than $100 million each, backed by investors betting that breakthroughs in magnets, lasers, and computation can finally translate into electricity—while several fou

For years, fusion sounded like a promise people made to themselves—always a decade away, always just out of reach. Now it’s showing up as an engineering schedule, a financing milestone, and a spreadsheet full of investor dollars.

Across the private fusion industry, a handful of startups have each raised more than $100 million. The money isn’t just a vote of confidence in a scientific dream. It’s also a sign of how urgently investors want fusion to stop being theoretical and start producing electricity—or revenue along the way.

The bullish wave behind the industry has been driven by three advances: more powerful computer chips. more sophisticated AI. and powerful high-temperature superconducting magnets. Those shifts have helped companies pursue more sophisticated reactor designs, run better simulations, and operate more complex control schemes.

The industry’s momentum got a major boost at the end of 2022, when a U.S. Department of Energy lab announced it produced a controlled fusion reaction that generated more power than the lasers had imparted to the fuel pellet. The experiment crossed what’s known as scientific breakeven. even though commercial breakeven—where the reaction produces more than the entire facility consumes—remains a long way off. Still, it was a milestone the private sector could build on.

Commonwealth Fusion Systems has become one of the clearest examples of where that confidence has gone. The Massachusetts company has raised about a third of all private capital invested in fusion companies to date. Its latest round closed in August and added $863 million, bringing its total raised near $3 billion.

That cash follows a Series B2 that came four years after its $1.8 billion Series B. which the company says helped it move into the lead position. Commonwealth Fusion Systems has been building Sparc in Massachusetts—its first-of-a-kind power plant intended to produce power at “commercially relevant” levels.

Sparc is a tokamak design, shaped like a doughnut, with a D-shaped cross section wound with high-temperature superconducting tape. When energized, the magnets generate a powerful magnetic field to contain and compress the superheated plasma. Heat generated from the reaction is converted to steam to power a turbine. Commonwealth Fusion Systems designed its magnets in collaboration with MIT. where co-founder and CEO Bob Mumgaard worked as a researcher on fusion reactor designs and high-temperature superconductors.

The company expects Sparc to be operational in late 2026 or early 2027. Later this decade. it says it will begin construction on Arc. a commercial power plant meant to produce 400 megawatts of electricity near Richmond. Virginia. Google has agreed to buy half of Arc’s output. Backers include Breakthrough Energy Ventures, The Engine, Bill Gates, and others.

In TAE Technologies, the story of big fundraising is tied to both fusion physics and an unexpected corporate turn. Founded in 1998 as Tri Alpha Energy, TAE Technologies spun out of the University of California, Irvine by Norman Rostoker. It uses a field-reversed configuration. with a twist: after two plasma shots collide in the middle of the reactor. the company bombards the plasma with particle beams to keep it spinning in a cigar shape. The approach is meant to improve plasma stability. allowing more time for fusion and more heat extraction to spin a turbine.

Then, in December 2025, TAE announced it would merge with President Donald Trump’s social media company, Trump Media & Technology Group. The all-stock transaction would value the combined company at $6 billion. TAE would receive $200 million plus another $100 million upon filing paperwork with the Securities and Exchange Commission. TAE CEO Michl Binderbauer would serve as co-CEO of the combined company alongside Devin Nunes. who had been sole CEO of Trump Media.

Before the merger, TAE had previously raised $150 million in June from existing investors including Google, Chevron, and New Enterprise. Before the merger, it had raised $1.79 billion in total, according to PitchBook.

Helion is pushing its timeline in a way that sounds almost impatient. The company plans to produce electricity from its reactor in 2028, and its first customer is Microsoft.

Helion, based in Everett, Washington, uses a field-reversed configuration. Magnets surround a reaction chamber shaped like an hourglass with a bulge at the point where the two sides come together. At each end of the hourglass. the reactor spins plasma into doughnut shapes that are shot toward each other at more than 1 million mph. When they collide in the middle, additional magnets help induce fusion. Once fusion occurs. it boosts the plasma’s own magnetic field. which induces an electrical current inside the reactor’s magnetic coils. Helion says that electricity is then harvested directly from the machine.

The company raised $465 million in June in a Series G that valued it at $15.5 billion. Its previous round, announced in January 2025, totaled $425 million. Across rounds, Helion says it has raised $1.5 billion. Investors include Sam Altman. SoftBank Vision Fund 2. Reid Hoffman. KKR. BlackRock. Peter Thiel’s Mithril Capital Management. and Capricorn Investment Group.

Some startups are aiming to get there through power in the moment. Pacific Fusion burst out of the gate with a Series A topped $1 billion, the startup told TechCrunch. Its approach uses inertial confinement, but instead of lasers compressing the fuel, it relies on coordinated electromagnetic pulses.

The timing is the challenge. The company says all 156 impedance-matched Marx generators need to produce 2 terawatts for 100 nanoseconds. and those pulses must converge on the target simultaneously. Pacific Fusion is led by CEO Eric Lander, the scientist who led the Human Genome Project, and president Will Regan.

Even with the huge headline funding, Pacific Fusion’s investors don’t pay everything at once. Its funding will be paid out in tranches when the company achieves specified milestones, an approach common in biotech.

Shine Technologies has taken a more cautious path—at least on what it sells first. Selling electrons from a fusion power plant is still years off. so the company is starting by selling neutron testing and medical isotopes. More recently, it has been developing a way to recycle radioactive waste. Shine hasn’t locked in a specific approach for a future fusion reactor. saying instead that it is developing necessary skills for when that time comes.

Shine has raised a total of $1 billion, according to PitchBook. Investors include Energy Ventures Group, Koch Disruptive Technologies, Nucleation Capital, and the Wisconsin Alumni Research Foundation. The company’s most recent round was a $240 million round in February led by NantWorks. with participation from investors including Deerfield Management. Fidelity Management & Research Company. Oaktree Capital Management. Pelican Energy Partners. and the Sumitomo Corporation of Americas.

General Fusion has reached a similar scale. but its path has been messier—illustrating how fragile timelines can be when a company is building hardware toward breakeven. The Richmond. British Columbia-based company has raised over $600 million and was founded in 2002 by physicist Michel Laberge. who wanted to prove magnetized target fusion (MTF).

In General Fusion’s reactor, a liquid metal wall surrounds a chamber where plasma is injected. Pistons push the wall inward to compress the plasma and spark a fusion reaction. Neutrons heat the liquid metal. which the company can circulate through a heat exchanger to generate steam to spin a turbine.

In spring 2025, General Fusion ran short of cash as it built LM26, its latest device hoped to hit breakeven in 2026. Just days after it hit a key milestone, it laid off 25% of its staff. CEO Greg Twinney penned an open letter pleading for funding from investors.

By August. investors delivered somewhat: General Fusion injected $22 million in a pay-to-play round that one investor called “the least amount of capital possible” to keep the company afloat. In November. securities filings in Canada revealed that the company raised $51.1 million in SAFE notes from nearly 70 investors. which the Globe and Mail reported. Altogether, General Fusion has raised $612 million, according to PitchBook.

In January, General Fusion said it would go public via a reverse merger with a special purpose acquisition company. If the deal closes as planned, General Fusion could bring in an additional $335 million.

Inertia Enterprises is betting on the momentum from the National Ignition Facility. Only one fusion experiment—NIF—has surpassed scientific breakeven, and Inertia’s founders include NIF chief scientist Annie Kircher. The founding team also includes Mike Dunne. a Stanford professor. and Jeff Lawson. who co-founded Twilio and currently owns The Onion.

In April, the startup signed three agreements to commercialize technology developed at the NIF. Inertia plans to use lasers to bombard fusion fuel pellets—an inertial confinement design echoing what Kircher successfully used at the NIF. Inertia emerged from stealth in February with $450 million in Series A funding led by Bessemer Venture Partners. with participation from GV. Modern Capital. Threshold Ventures. and others.

Focused Energy, based in Germany, traces its lineage to NIF as well. It uses laser pulses to compress a fuel target. and it hired Debbie Callahan as its chief strategy officer—Callahan helped design the fuel target at NIF. Her job at Focused Energy is to figure out how to turn NIF’s painstakingly crafted fuel target into something that can be mass manufactured at a rate of nearly 1 million per day.

Focused Energy raised an oversubscribed $240 million Series A in June, bringing its total private capital raised to $400 million. The company has received $200 million in grants as well. Investors include the German Federal Agency for Breakthrough Innovation (SPRIND). Prime Movers Lab. and the utility RWE. which granted Focused Energy access to a decommissioned nuclear fission power plant it operates.

Tokamak Energy takes a compressed tokamak approach. It uses a usual tokamak doughnut shape. but squishes it—reducing aspect ratio so the outer bounds start resembling a sphere. Like other tokamak-based startups, it uses high-temperature superconducting magnets of the REBCO variety. Because its design is more compact than a traditional tokamak. it says it requires less in the way of magnets. which should reduce costs.

The Oxfordshire. U.K.-based startup’s ST40 prototype. which looks like a large. steampunk Fabergé egg. generated an ultra-hot 100-million degree Celsius plasma in 2022. Its next generation. Demo 4. is currently under construction and is intended to test the company’s magnets in “fusion power plant-relevant scenarios.” Tokamak Energy raised $125 million in November 2024 to continue its reactor design and expand its magnet business. In April. it said it would be supplying magnets for the U.K.’s STEP Fusion program. a government program working toward a spherical tokamak-based power plant.

In total, Tokamak Energy has raised $336 million from investors including Future Planet Capital, In-Q-Tel, Midven, and Capri-Sun founder Hans-Peter Wild, according to PitchBook.

Zap Energy is aiming for fusion without high-temperature superconducting magnets or powerful lasers. Instead, it zaps plasma with an electric current that generates its own magnetic field. That magnetic field compresses plasma to about 1 millimeter, at which point ignition occurs. The neutrons released by the fusion reaction bombard a liquid metal blanket surrounding the reactor, heating it up. The liquid metal is then cycled through a heat exchanger where it produces steam to drive a turbine.

In April, Zap Energy announced a partial pivot toward a hybrid power plant that employs both nuclear fusion and fission. It also hired a new CEO, Zabrina Johal, who has expertise in the fission industry. Zap says the move will help it bring in revenue earlier than fusion alone.

The Everett, Washington-based company has raised $327 million, according to PitchBook. Backers include Bill Gates’ Breakthrough Energy Ventures, DCVC, Lowercarbon, Energy Impact Partners, Chevron Technology Ventures, and Bill Gates as an angel.

Type One Energy is planning a fusion reactor at the site of a retired Tennessee Valley Authority coal power plant. The magnetic confinement device is expected to generate 350 megawatts of electricity, and the company hopes to bring it online by the mid-2030s.

Unlike other fusion startups. Type One plans to sell key technology to organizations like the TVA. allowing them to build. own. and operate the equipment—similar to how many fossil fuel power plants are developed today. Type One has raised $269 million to date. including an $87 million equity round in advance of a $250 million Series B that the company is currently raising.

Proxima Fusion is bucking the trend toward tokamaks and inertial confinement. It raised a €130 million Series A that brings its total raised to more than €185 million. Investors include Balderton Capital and Cherry Ventures.

Proxima says stellarators are similar to tokamaks in that they confine plasma in a ring-like shape using powerful magnets. but with a twist: stellarators twist and bulge to accommodate the plasma’s quirks. The company’s goal is a plasma that stays stable longer, increasing the chances of fusion reactions.

Kyoto Fusioneering has put money into the “balance of plant”—the components outside a fusion reactor that can still make or break commercialization. The so-called balance of plant. it says. ranges from gyrotrons that heat plasma to heat extraction systems for harvesting power from fusion reactions and turning it into electricity.

Kyoto Fusioneering says it is betting that if even one fusion startup succeeds in generating enough power to sell to the grid. the industry will need a supplier for the balance of plant and the expertise to integrate it into whichever fusion technologies win out. Venture capitalists appear to agree: they have invested $191 million in Kyoto Fusioneering. with investors including 31Ventures. In-Q-Tel. JIC Venture Growth Investments. Mitsubishi. and Sumitomo Mitsui Trust Investment.

Marvel Fusion is building toward inertial confinement. using a technique it says follows the basic approach used at the National Ignition Facility to prove that controlled nuclear fusion reactions could produce more power than was needed to kick them off. Marvel fires powerful lasers at a target embedded with silicon nanostructures that cascade under bombardment. compressing the fuel to the point of ignition. Because the target is made using silicon. Marvel says it should be relatively simple to manufacture. leveraging the semiconductor manufacturing industry’s decades of experience.

Marvel expects to have a demonstration facility operational by 2027. The company is building it in collaboration with Colorado State University. Munich-based Marvel has raised a total of $162 million from investors including b2venture. Deutsche Telekom. Earlybird. and HV Capital. with Taavet Hinrikus and Albert Wenger as angels.

Thea Energy is going after the cost problem in stellarators. Stellarators can keep plasmas burning for long periods of time, but they require twisty magnetic fields. Many stellarators build magnets mimicking that complex shape. Thea Energy says it wreathes its doughnut-shaped reactor in dozens of smaller magnets and uses control software to create the necessary kinks.

In May, Thea raised $100 million in a Series B led by the U.S. Innovative Technology Fund, a little more than two years after a $20 million Series A. Across all rounds, the startup has raised $130 million in private capital. Other investors include Prelude Ventures, Lowercarbon Capital, Hitachi Ventures, and Emerald Technology Ventures.

First Light Fusion takes another divergence in inertial confinement. While it compresses fusion fuel pellets until ignition—like other inertial confinement approaches—it doesn’t rely on lasers doing the compression work. Instead, it fires a projectile at a target using a two-stage gun. The first stage uses gunpowder to fire a plastic piston that compresses hydrogen to 145,000 psi, launching the projectile. The target is designed to amplify impact force so it compresses the fuel to the point of ignition.

In March 2025, First Light Fusion announced it would not pursue building its own power plant. Instead, it said it would offer its core technologies to other companies to build one. A First Light spokesperson said it is planning to build “pulsed power capability that would act as our demonstrator plant but would have other science and defense applications.” In other words. the company said it was dropping plans for a power plan in a quest for revenue.

Based in Oxfordshire, U.K., First Light has raised $108 million from investors including Invesco, IP Group, and Tencent, according to PitchBook.

Xcimer is going back to the NIF-inspired foundation and scaling it up. The Colorado-based startup is planning to build a 10-megajoule laser system—5x more powerful than the NIF setup that made history. It plans molten salt walls around the reaction chamber to absorb heat and protect the first solid wall from damage. In June, Xcimer turned on Phoenix, which it says is the most powerful privately owned laser in the world.

Founded in July 2022, Xcimer has raised $100 million from investors including Hedosophia, Breakthrough Energy Ventures, Emerson Collective, Gigascale Capital, and Lowercarbon Capital.

Taken together. the roster shows how many paths fusion investors are willing to fund—and how quickly those bets are being stress-tested by engineering timelines. Some companies are racing toward electricity by specific years. while others are selling components or adjacent products because commercialization is still years away.

That gap—between scientific milestones and the first reliable revenue stream—sits at the center of why these rounds matter. In fusion, the next milestone doesn’t just move a project forward. It determines whether teams keep building. whether factories get planned. and whether investors stay in the room long enough to see the sun made practical.

fusion power startups Commonwealth Fusion Systems Helion TAE Technologies General Fusion Tokamak Energy Zap Energy Type One Energy investor funding superconducting magnets inertial confinement stellarator lasers magnets Nevada Kyoto Fusioneering Thea Energy Xcimer First Light Fusion