Private fusion companies have raised more than six billion dollars since 2021. No company has delivered net electricity yet. This traces the money against the promises, and lets you check each one for yourself.
The funding timeline
Tap any company to see what it has actually built, what it has promised, and how those two things compare.
Swipe sideways to see the full 2021 to 2033 timeline →
Built so farCFS demonstrated a 20 tesla magnet in 2021, the strongest fusion relevant magnet ever built. That result is why it raised $1.8B that December. It is now building a reactor called SPARC in Devens, Massachusetts, funded partly by a further $683M round in August 2025.
What it has promisedCFS wants SPARC to reach a Q value above 2, meaning it puts out more than twice the energy it takes to run, by around 2027. A commercial plant called ARC would follow in the early 2030s.
Worth knowingThe best result any tokamak has ever hit is a Q of 0.67, set in 1997 and never beaten since. SPARC needs roughly three times that. The magnet is a proven breakthrough. The Q above 2 result is still a promise.
Built so farHelion uses a pulsed approach called a field reversed configuration, burning deuterium and helium 3. It claims it can convert the reaction straight into electricity, skipping the steam turbine most power plants rely on. It has raised roughly $500M in equity across 2021 and 2025, plus $1.7B in milestone based commitments. Sam Altman personally put in $375M and later stepped down from the board. Helion is now building its seventh generation machine, called Polaris.
What it has promisedIn May 2023 Helion signed the fusion industry’s first commercial power purchase agreement, promising Microsoft electricity by 2028.
Worth knowingHelion’s fuel cycle needs temperatures around 600 million degrees, about six times hotter than the deuterium tritium reaction every other company on this page is chasing. No experiment has reached those conditions at a useful scale, and helium 3 is one of the rarest substances on Earth. Most independent physicists see the 2028 date as very unlikely, even if the underlying idea is worth watching.
Built so farTAE uses a beam driven field reversed configuration and is aiming for a proton boron fuel cycle, which produces almost no neutrons. It raised $250M in July 2022, one round within a longer funding history that totals over $1.2B. It is now building a machine called Copernicus.
What it has promisedA commercial plant in the early 2030s.
Worth knowingProton boron fusion needs even higher temperatures than deuterium tritium, making it arguably the hardest fuel cycle on this page. It also produces the least radioactive waste if the physics works out.
Built so farPacific Fusion raised $900M in October 2024, one of the largest single rounds in fusion history.
What it has promisedNo specific delivery timeline for Pacific Fusion appears in the sources behind this piece.
Worth knowingA round this large with so little public technical detail is its own signal. Sophisticated investors moved before a public roadmap existed, which says something about how they are pricing the field as a whole.
Built so farProxima raised €411M, about $468M, in mid 2026, pushing its valuation to nearly €2.5B and making it Europe’s most valuable fusion company. Its design builds on Germany’s Wendelstein 7-X, a stellarator that holds the record for the longest high performance plasma confinement ever achieved.
What it has promisedProxima is using this capital to build Alpha, a stellarator meant to demonstrate net energy gain. No public target date for Alpha appears in the sources behind this piece.
Worth knowingA tokamak needs a continuous internal plasma current, which can suddenly collapse and dump energy into the machine. A stellarator does not carry that risk, which matters for something meant to run continuously like a real power plant. The tradeoff is a far more complex shape to build.
Built so farInertia raised $450M in February 2026.
What it has promisedNo public delivery timeline appears in the sources behind this piece yet.
Worth knowingA newer entrant. Worth tracking as more technical detail becomes public.
Built so farFocused Energy raised $240M in May 2026.
What it has promisedNo public delivery timeline appears in the sources behind this piece yet.
Worth knowingA newer entrant. Worth tracking as more technical detail becomes public.
The industry’s only disclosed PPA
In May 2023, Helion signed the first commercial fusion power purchase agreement anyone has disclosed, promising Microsoft electricity by 2028. Of the seven companies in the timeline above, it is the only one with a public commercial contract of this kind.
The agreement includes financial penalties if Helion fails to deliver, according to public reporting on the deal. The exact penalty terms have not been made public.
A missed date would do more than cost Helion money. This was the first corporate fusion PPA anyone signed. If it fails, it becomes the reference point every future fusion contract gets measured against, and a harder case for the next company trying to sign one.
Helion’s fuel cycle also needs conditions no experiment has reached yet, so the physics risk and the contract risk are tied together here in a way most energy PPAs never have to deal with.
Elsewhere in fusion
These four raised real money too, but public sources behind this piece did not include dated funding rounds for them, so they sit outside the timeline above.
A spherical tokamak built around a compact high temperature superconductor design. Building the ST80-HTS machine in the UK, targeting commercial operation in the 2030s.
Uses mechanical plasma compression instead of magnets or lasers. Building a demonstration plant at Culham in the UK, targeting the late 2020s.
Uses a z pinch approach that needs no external magnets to hold the plasma. Its demonstration system began operating in 2024.
Fires a hypersonic projectile at a fuel target instead of using magnets or lasers directly. Demonstrated fusion in 2022 and is targeting the 2030s for further progress.
Five problems no one has solved yet
Every company above still has to clear these, regardless of how much it has raised.
Can they actually deliver
- The HTS magnet breakthrough behind CFS is real, and it changes the cost math for building a compact tokamak.
- Private capital moves faster than government labs, and several different approaches are being tested in parallel rather than in sequence.
- Machine learning is already improving plasma control. Google DeepMind published a real time tokamak control result in Nature back in 2022.
- Microsoft, Google, and Nucor Steel are putting real money behind future fusion power. That kind of demand signal is hard to fake.
- Every energy technology gets cheaper as it scales up. The first fusion plant will be expensive. The tenth one might not be.
- Seventy plus years and billions of dollars of research have produced zero net electricity from fusion so far.
- Company timelines are also fundraising documents. Nearly every fusion delivery date in history has slipped.
- ITER is a $25B international project staffed by the best fusion engineers in the world, and it is still behind schedule. Startups face the same physics with a fraction of that budget.
- The tritium supply problem has no financial shortcut. Money cannot speed up how fast materials absorb neutron damage.
- Solar and battery costs keep falling every year. By the time fusion is ready, it may be competing against clean energy that is already extremely cheap.
Fusion will very likely arrive too late to help hit near term climate targets. But climate work does not stop once the world reaches net zero. Heavy industry and a growing global south will keep needing enormous amounts of firm clean power well after that point. A one to two billion dollar a year global bet on fusion is a small insurance policy against a very large problem, even if it is not the main plan.
Figures and claims are drawn from public company announcements, press coverage, and published technical reporting current as of July 2026. Funding totals and delivery dates belong to the companies that stated them, not to independent verification. Nothing on this page is investment advice.
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