Every fusion startup that has raised over $100M

Fusion power has finally shaken off the “always decades away” joke and turned into one of the hottest bets in climate tech.

Cheaper computing, better AI and high‑temperature superconducting magnets have pushed reactor design from whiteboard sketches into hardware. The U.S. Department of Energy’s National Ignition Facility (NIF) also helped, hitting scientific breakeven in 2022 with a controlled fusion reaction that produced more energy than the lasers delivered to the fuel pellet.

Commercial breakeven — where a plant produces more power than the entire facility consumes — is still ahead. But investors are already writing big checks.

Below is a company‑by‑company look at every fusion startup that has raised more than $100 million, based on TechCrunch reporting and PitchBook data.

Commonwealth Fusion Systems (CFS)

• Total raised: nearly $3 billion
• Approach: Tokamak with high‑temperature superconducting magnets
• Location: Massachusetts, U.S.

Commonwealth Fusion Systems has soaked up roughly a third of all private fusion capital so far.

In August 2025, CFS closed an $863 million Series B2, four years after its $1.8 billion Series B, cementing its position as the best‑funded fusion startup on the planet.

CFS is building Sparc, a compact tokamak power plant in Massachusetts. The D‑shaped plasma is confined by coils wound with high‑temperature superconducting tape, generating a powerful magnetic field that squeezes superheated plasma. Heat from the reaction is converted to steam and routed through a turbine.

The company co‑designed its magnets with MIT, where co‑founder and CEO Bob Mumgaard worked on fusion reactor designs and superconductors. CFS expects Sparc to be operational in late 2026 or early 2027.

Next up is Arc, a full commercial plant targeting 400 megawatts of electricity near Richmond, Virginia. Google has already agreed to buy half of Arc’s output. Investors include Breakthrough Energy Ventures, The Engine, Bill Gates and others.

TAE Technologies

• Total raised (pre‑merger): $1.79 billion
• Approach: Field‑reversed configuration with particle beams
• Founded: 1998
• Location: California, U.S.

TAE Technologies is one of the veterans of the sector. Originally Tri Alpha Energy, it spun out of UC Irvine in 1998, founded by physicist Norman Rostoker.

TAE uses a field‑reversed configuration (FRC). Two plasma shots collide in the center of the reactor, then the company bombards the resulting cigar‑shaped plasma with particle beams to keep it spinning. The point is stability: more stable plasma means more time for fusion reactions and more heat to drive a turbine.

In June 2025, TAE raised $150 million from existing backers including Google, Chevron and New Enterprise Associates. By then it had raised $1.79 billion, according to PitchBook.

In December 2025, TAE announced an all‑stock merger with Trump Media & Technology Group, valuing the combined company at $6 billion. TAE would receive $200 million plus another $100 million upon filing paperwork with the U.S. Securities and Exchange Commission. CEO Michl Binderbauer will become co‑CEO alongside Devin Nunes.

Helion

• Total raised: $1.03 billion
• Approach: Field‑reversed configuration with direct electricity capture
• Target date for first power sale: 2028
• Location: Everett, Washington, U.S.

Helion is running the most aggressive clock in fusion. The company says it will produce electricity in 2028, with Microsoft signed up as its first customer.

Helion’s reactor is another FRC design, but with a twist aimed at direct power generation. Magnets shape an hourglass‑like chamber with a bulge at the center. At each end, the system spins plasma into doughnut shapes and fires them toward each other at over 1 million mph. When they collide, additional magnets drive them into fusion.

When fusion happens, the plasma’s magnetic field surges and induces an electric current directly in the surrounding coils. Instead of just making heat for steam, Helion harvests that current straight from the machine.

Helion raised $425 million in January 2025, around the time it powered up Polaris, its latest prototype reactor. The company has raised $1.03 billion in total, according to PitchBook. Investors include Sam Altman, Reid Hoffman, KKR, BlackRock, Peter Thiel’s Mithril Capital Management and Capricorn Investment Group.

Pacific Fusion

• Total raised: $900 million Series A (paid in milestones)
• Approach: Inertial confinement using electromagnetic pulses
• Location: U.S.

Pacific Fusion skipped the seed and growth stages and went straight to a mammoth $900 million Series A.

Instead of lasers, the company uses inertial confinement via coordinated electromagnetic pulses. The setup relies on 156 impedance‑matched Marx generators that must deliver 2 terawatts for 100 nanoseconds, with all pulses converging on the fuel target at precisely the same moment.

The company is led by Eric Lander — the scientist who led the Human Genome Project — as CEO, and Will Regan as president.

The money isn’t wired all at once. Investors will pay out the $900 million in tranches tied to technical milestones, an approach borrowed from biotech.

Shine Technologies

• Total raised: $778 million
• Approach: Stepwise path: neutrons, isotopes, waste, then power
• Location: U.S.

Shine Technologies is taking a more incremental path. Instead of racing straight to a grid‑scale plant, it’s using fusion‑related hardware to sell neutron testing services and medical isotopes today. More recently, it has been developing radioactive waste recycling technology.

Shine has not yet committed to a specific reactor design for a future power plant. Instead, it argues that building up skills around fusion, high‑energy neutrons and nuclear systems is the best way to be ready when the physics and economics line up.

The company has raised $778 million, according to PitchBook. Backers include Energy Ventures Group, Koch Disruptive Technologies, Nucleation Capital and the Wisconsin Alumni Research Foundation.

General Fusion

• Total raised: $492 million
• Approach: Magnetized target fusion with liquid metal and pistons
• Founded: 2002
• Location: Richmond, British Columbia, Canada

General Fusion has been at this for over two decades. Founded in 2002 by physicist Michel Laberge, the company is pursuing magnetized target fusion (MTF).

In General Fusion’s design, a liquid metal wall forms a spherical chamber. Plasma is injected inside, and a ring of mechanical pistons slams the liquid metal inward, compressing the plasma and triggering fusion. Neutrons from the reaction heat the liquid metal, which then passes through a heat exchanger to make steam for a turbine.

Investors include Jeff Bezos, Temasek, BDC Capital and Chrysalix Venture Capital.

The company hit a rough patch in spring 2025 while building LM26, the device it hoped would hit breakeven in 2026. General Fusion ran short of cash and laid off 25% of staff just days after a key milestone. CEO Greg Twinney published an open letter appealing for more capital.

In August 2025, investors put in $22 million in a pay‑to‑play round that one investor described as “the least amount of capital possible” to keep the company alive. Then in November, Canadian securities filings showed General Fusion had raised $51.1 million in SAFE notes from nearly 70 investors, according to the Globe and Mail.

Altogether, General Fusion has raised $492 million, according to PitchBook.

Tokamak Energy

• Total raised: $336 million
• Approach: Compact spherical tokamak with REBCO magnets
• Location: Oxfordshire, U.K.

Tokamak Energy takes the classic tokamak and squeezes it.

Rather than a large doughnut, its spherical tokamak design reduces the aspect ratio until the machine resembles a metal sphere. The result: a more compact reactor that should need fewer high‑temperature superconducting magnets, cutting costs.

The company’s magnets use rare earth barium copper oxide (REBCO) tape. In 2022, its ST40 prototype — a large, almost steampunk Fabergé egg — reached 100 million°C plasma.

Tokamak Energy is now building Demo 4 to test its magnets in “fusion power plant‑relevant scenarios.” The company raised $125 million in November 2024, bringing total funding to $336 million, according to PitchBook. Backers include Future Planet Capital, In‑Q‑Tel, Midven and Capri‑Sun founder Hans‑Peter Wild.

Zap Energy

• Total raised: $327 million
• Approach: Sheared‑flow z‑pinch‑style confinement via electric current
• Location: Everett, Washington, U.S.

Zap Energy skips both enormous magnets and mega‑lasers. Instead, it drives a strong electric current through plasma, which generates its own magnetic field. That self‑field pinches the plasma down to about 1 millimeter, where ignition occurs.

Neutrons from the fusion reaction hit a liquid metal blanket surrounding the reactor, heating it up. The hot liquid metal then runs through a heat exchanger to make steam and power a turbine.

Like Helion, Zap is based in Everett, Washington. It has raised $327 million, according to PitchBook. Investors include Bill Gates’ Breakthrough Energy Ventures, DCVC, Lowercarbon, Energy Impact Partners, Chevron Technology Ventures and Bill Gates as an angel.

Proxima Fusion

• Total raised: more than €185 million
• Latest round: €130 million Series A
• Approach: Stellarator
• Location: Germany

Most of the big fusion checks have gone to tokamaks, FRCs and inertial confinement. Proxima Fusion is a rare stellarator startup breaking through that bias.

The company raised a €130 million Series A, bringing its total to more than €185 million....