Science
Fusion startups are drawing billions in private capital
Fusion startups are drawing billions in private capital, with Commonwealth Fusion Systems, Helion and others pursuing distinct reactor designs and timelines.
Fusion startups are attracting billions in private capital as advances in computing, AI and high-temperature superconducting magnets make reactor designs and plasma-control systems more sophisticated. The sector also gained momentum after a U.S. Department of Energy laboratory achieved scientific breakeven in late 2022, producing more energy from a controlled fusion reaction than the lasers delivered to the fuel pellet—though commercial breakeven, including the energy consumed by the entire facility, remains a higher bar.
According to TechCrunch, data from FusionX identifies the following private fusion companies with more than $100 million in committed capital.
The largest fusion bets
Commonwealth Fusion Systems leads the private market with $3.94 billion raised, including a $1 billion round closed in July. Its Sparc reactor in Massachusetts uses a tokamak design: high-temperature superconducting tape generates magnetic fields that confine and compress plasma, with the resulting heat converted to steam for a turbine.
CFS expects Sparc to become operational in late 2026 or early 2027 and says it could reach scientific breakeven, or Q > 1, in 2027. The company plans to begin construction later this decade on Arc, a 400-megawatt commercial plant near Richmond, Virginia. Google has agreed to buy half of Arc’s output.
Helion has raised $3.2 billion and is pursuing the industry’s most aggressive stated schedule: producing electricity from a reactor in 2028, with Microsoft as its first customer. Its field-reversed configuration accelerates plasma into doughnut-shaped rings and collides them at more than 1 million mph. The resulting magnetic changes induce electrical current directly in the reactor’s coils, avoiding a conventional steam-turbine path.
The Everett, Washington-based company raised $465 million in June in a Series G that valued it at $15.5 billion. Its investors include Sam Altman, SoftBank Vision Fund 2, Reid Hoffman, KKR, BlackRock, Peter Thiel’s Mithril Capital Management and Capricorn Investment Group.
TAE Technologies, founded in 1998 as Tri Alpha Energy, has raised $1.65 billion before its proposed merger with Trump Media & Technology Group. Its field-reversed configuration uses particle beams to keep the colliding plasma stable in a cigar-shaped form, allowing more time for fusion and heat extraction.
Announced in December 2025, the all-stock transaction would value the combined company at $6 billion. TAE would receive $200 million, plus another $100 million when regulatory paperwork is filed with the Securities and Exchange Commission. The companies said the combined entity would have two co-CEOs: TAE CEO Michl Binderbauer and Trump Media CEO Kevin McGurn, who is serving as interim CEO.
Pacific Fusion raised more than $1 billion in Series A funding, although investors will provide the capital in milestone-based tranches. The company is using inertial confinement, replacing lasers with synchronized electromagnetic pulses. Its system requires 156 impedance-matched Marx generators to deliver 2 terawatts for 100 nanoseconds, with the pulses converging on the target simultaneously.
The company is led by CEO Eric Lander, who led the Human Genome Project, and chief scientist Will Regan.
Different reactor designs, different paths to revenue
Proxima Fusion has raised more than $682.9 million, according to FusionX, and was valued at $2.7 billion in its July funding round. The Germany-based startup is developing stellarators, which use twisted, irregular magnetic chambers to keep plasma stable for longer than a conventional ring-shaped design. It plans to complete Alpha, a net-energy demonstrator, in the early 2030s, followed later that decade by its commercial Stellaris plant.
Shine Technologies is not yet selling electricity from fusion. Instead, it has raised $1 billion to build businesses around neutron testing, medical isotopes and radioactive-waste recycling while it develops the expertise needed to select a future reactor design. Its most recent funding was a $240 million round in February, led by NantWorks.
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 surpassed scientific breakeven, along with Stanford professor Mike Dunne and Twilio co-founder Jeff Lawson. Inertia plans to use lasers to compress fusion fuel pellets and signed three agreements in April to commercialize technology developed at NIF.
General Fusion has raised more than $442 million. The Richmond, British Columbia-based company’s magnetized target fusion design injects plasma into a chamber surrounded by liquid metal, then uses pistons to compress the metal and plasma. Neutrons heat the liquid metal, which can circulate through a heat exchanger to generate steam.
The company faced a cash shortage while building its LM26 device, which it hoped would reach breakeven in 2026. It cut 25% of its staff after reaching a key milestone, then raised $22 million in an August 2025 pay-to-play round and $51.1 million in SAFE notes disclosed in November. General Fusion listed on Nasdaq on July 13, 2026, after a reverse merger that generated $127 million, according to FusionX.
Zap Energy has raised $325 million with a design that uses an electrical current to create its own magnetic field, compressing plasma to roughly 1 millimeter. A liquid-metal blanket absorbs neutron energy, which can then be used to produce steam.
In April, Zap announced a partial pivot into nuclear fission and a possible hybrid fusion-fission power plant. It also hired Zabrina Johal as CEO; the company says the move could generate revenue earlier than a fusion-only strategy.
Tokamak Energy is developing a compact, spherical version of the conventional tokamak and uses rare-earth barium copper oxide, or REBCO, superconducting magnets. Its ST40 prototype produced a 100-million-degree Celsius plasma in 2022, while the Demo 4 system is under construction to test the magnets in conditions relevant to a fusion power plant.
The U.K.-based startup has raised $284 million, including a $125 million round in November 2024. In April, it said it would supply magnets for the U.K. government’s STEP Fusion program.
TechCrunch’s list also includes Germany-based Focused Energy, another company linked to the National Ignition Facility. The available reporting says it uses laser pulses to compress a fuel target and has hired Debbie Callahan as chief scientist; it does not provide a funding total or further details in the supplied report.