What are the top nuclear fusion startups by revenue today?

The ranking of top startups in the nuclear fusion market by revenue

Below is a table ranking all the companies in this market by their current revenue scale. You can find our methodology at the end of this page.

If you want a deeper understanding of the market and its current dynamics, get our report covering the nuclear fusion market.

Are nuclear fusion startups finally making real money?

Nuclear fusion startups are attracting record investment and signing increasingly large commercial contracts, but most companies developing fusion power plants still generate little or no revenue from their core technology. The biggest businesses by funding are not necessarily the biggest by sales.

The Fusion Industry Association's 2026 survey provides a striking contrast. Across 56 fusion companies, the industry raised $4.48 billion in the preceding 12 months, a 69% increase from the previous year's funding. Cumulative funding reported since the association began its annual surveys in 2021 reached $14.24 billion, while employment exceeded 16,000 people.

Yet one of the most revealing financial disclosures came from General Fusion. In its 2026 SEC filings, the Canadian company acknowledged that it had never generated revenue, despite having developed its technology for years and accumulated a deficit of approximately $457 million by June 2026.

Other companies are beginning to show a different commercial trajectory. Commonwealth Fusion Systems secured an electricity purchase agreement worth more than $1 billion with Eni in September 2025. Tokamak Energy won a £70 million engineering contract in April 2026. TAE Technologies disclosed approximately $1.21 million in consolidated annual sales in its SEC financial statements.

These figures describe three very different commercial situations: future electricity suppliers, companies selling fusion-related engineering equipment, and research-intensive developers preparing for eventual commercialization.

The clearest finding is that fusion's commercial supply chain is already generating revenue while the developers of utility-scale fusion power plants remain largely pre-revenue. That distinction changes which companies can reasonably be considered industry leaders today.

What counts as a nuclear fusion startup by revenue?

A nuclear fusion startup can generate revenue without selling electricity, but not every organization receiving money to develop fusion technology has established a commercial business.

We can distinguish three economically meaningful groups. The first consists of reactor developers such as Commonwealth Fusion Systems, Helion Energy, General Fusion, TAE Technologies and Zap Energy. Their ultimate objective is to sell fusion-generated electricity or commercially deploy fusion systems.

The second consists of fusion equipment and engineering businesses such as Kyoto Fusioneering, Tokamak Energy and Oxford Sigma. These companies can sell heating systems, superconducting magnets, materials technology, diagnostic equipment and engineering services long before commercial fusion power becomes available.

The third group includes publicly financed fusion development organizations, such as UK Fusion Energy, which may report accounting income derived from government funding rather than sales to independent customers.

For a revenue comparison, we treat recognized company sales as the strongest evidence, followed by disclosed customer contracts and other measurable commercial activity. Funding raised, grants, future electricity purchase agreements and estimated potential revenue remain separate.

A company can secure billions in financing without having sold any electricity. Meanwhile, a much smaller supplier can earn actual revenue by providing components to laboratories and reactor developers.

Which nuclear fusion companies have the most verified revenue today?

TAE Technologies, Tokamak Energy and several specialized suppliers have measurable commercial activity, but there is no sufficiently complete public revenue dataset to establish a definitive industry-wide ranking of independent fusion startups.

The available evidence gives us a more useful picture than a conventional top-ten list. Companies with reported sales can be identified separately from companies whose commercial scale is demonstrated through contracts, equipment orders or future electricity commitments.

For example, TAE Technologies reported $1.214 million in consolidated sales for its fiscal year ending March 2026. Tokamak Energy has a historical turnover figure of £872,000 for 2024, alongside a much larger recently awarded engineering contract. Next Hydrogen Solutions reported C$3.42 million of fiscal 2025 revenue, although it primarily develops hydrogen electrolyzer technology and its revenue is not attributable to nuclear fusion.

UK Fusion Energy reported £106.629 million of accounting revenue for its financial year ending March 2026. However, its audited accounts identify this entire amount as government grant-in-aid. It is a publicly owned development organization rather than an independent commercial fusion startup, so placing it first in a commercial startup ranking would give readers the wrong impression.

The following comparison separates verified sales, accounting income and commercial commitments instead of treating them as interchangeable.

Company	Reported amount	Type of evidence	What it establishes
UK Fusion Energy	£106.6M	FY2025/26 accounting revenue	Government grant-in-aid, not customer sales
Next Hydrogen Solutions	C$3.42M	FY2025 revenue	Company-wide hydrogen technology sales, not fusion-specific
TAE Technologies	$1.21M	FY2026 consolidated sales	Recognized revenue, including non-fusion activities
Tokamak Energy	£872K	FY2024 turnover	Historical company sales
American Fusion	$58K	Q2 2026 revenue	Small quarterly sales, fusion attribution uncertain
Tokamak Energy	£70M	STEP engineering contract	Contracted future work, not annual revenue
Kyoto Fusioneering	£6.59M	UK fusion equipment contract	Awarded contract value, including VAT
Commonwealth Fusion Systems	More than $1B	Future electricity purchase agreement	Potential future sales, not current revenue
Helion Energy	50 MW	Future electricity supply agreement	Contracted power capacity, not reported revenue
General Fusion	$0	SEC-disclosed revenue history	No revenue generated since inception

Is Commonwealth Fusion Systems the biggest nuclear fusion startup?

Commonwealth Fusion Systems is one of the industry's largest and most commercially significant private fusion developers, but its financial strength should not be confused with realized electricity revenue.

The Massachusetts company has attracted multibillion-dollar investment commitments to develop high-temperature superconducting magnet technology, its SPARC demonstration machine and the planned ARC power plant.

Its September 2025 agreement with Eni is a major milestone because it establishes a named corporate buyer for electricity from the company's first planned ARC facility in Chesterfield County, Virginia. The agreement exceeds $1 billion and concerns a plant designed to produce approximately 400 megawatts of electricity.

A $1 billion electricity commitment is vastly larger than the annual sales reported by most independent fusion technology developers. But the agreement concerns future supply, not $1 billion of earned revenue.

The ARC plant is expected to connect to the grid in the early 2030s. The Eni agreement demonstrates potential demand and commercial credibility while leaving important questions about delivery timing, plant economics and actual revenue unanswered.

That makes Commonwealth Fusion Systems a leading contender for future electricity revenue, though not a verified leader in revenue being generated today.

How much revenue does TAE Technologies make?

TAE Technologies reported approximately $1.21 million in consolidated sales for its fiscal year ending March 2026, making it one of the relatively few prominent fusion developers with a specific recent revenue figure in publicly accessible financial documentation.

The amount appears in SEC financial information associated with TAE's corporate transaction disclosures. It provides a firmer basis for assessing commercial activity than company valuations or financing announcements alone.

However, these sales are not equivalent to revenue from a commercial nuclear fusion power plant. TAE has developed technologies and business activities extending beyond electricity generation, meaning its consolidated financial figures cannot be treated as pure fusion electricity revenue.

General Fusion explicitly reported no revenue in its SEC disclosures, while Commonwealth Fusion Systems and Helion Energy have announced major future electricity commitments without establishing comparable current electricity sales.

TAE's sales show that a fusion-focused developer can earn money before commercial power generation. They don't demonstrate that the company's central reactor technology has become a profitable electricity business.

It's an important early commercial result, but nowhere near enough to establish TAE as the industry's overall revenue leader.

Is Tokamak Energy becoming a real commercial business?

Tokamak Energy has moved beyond laboratory development into meaningful commercial engineering contracts, and its £70 million STEP award is one of the clearest examples of fusion-related technology attracting major customers before commercial reactors begin producing electricity.

The British company originally concentrated on compact tokamak reactors and high-temperature superconducting magnets. It subsequently developed a distinct commercial opportunity around magnet technology, which has applications in fusion and other industrial systems.

In April 2026, UK Fusion Energy selected Tokamak Energy as the magnet systems partner for the government's Spherical Tokamak for Energy Production programme. The £70 million contract covers work through March 2029, including magnet architecture, superconducting systems engineering and plasma-facing integration.

That award represents approximately 80 times Tokamak Energy's reported £872,000 turnover for 2024. The comparison does not mean annual revenue has multiplied 80-fold, because the contract covers multiple years and its value will not necessarily be recognized evenly.

Still, the change in contracted commercial scale is substantial. Tokamak Energy is increasingly positioned to earn revenue from technologies that other fusion developers need, regardless of when its own reactor designs become commercially viable.

Few fusion developers have demonstrated such a clear route to monetizing their engineering capabilities before electricity generation begins.

Can Kyoto Fusioneering make money before commercial fusion exists?

Kyoto Fusioneering has a credible route to commercialization through reactor components and engineering systems, although its publicly documented contract awards do not establish a complete annual revenue figure.

The Japanese company focuses on the technologies needed to build and operate fusion facilities, including heating systems and other engineering infrastructure. Those products address immediate needs among research programs and reactor developers.

A notable example is the approximately £6.59 million gyrotron procurement contract awarded by UK Fusion Energy in July 2026. The published award value includes VAT, and delivery is scheduled over a period extending toward March 2029.

Gyrotrons are specialized microwave systems used to heat plasma. Customers need these technologies during reactor development, before they have a functioning power plant capable of selling electricity.

The comparison with Tokamak Energy and Oxford Sigma illustrates a wider market pattern. Tokamak Energy supplies superconducting magnet expertise, Kyoto Fusioneering provides heating and engineering capabilities, and Oxford Sigma addresses specialized materials and reactor components.

All three can participate in the fusion industry's spending cycle without first proving that a full-scale fusion plant can produce competitive electricity.

Kyoto Fusioneering therefore belongs among the more commercially advanced fusion equipment startups, even though available contract values cannot be converted into verified annual revenue.