What are the most valued startups in the nuclear fusion market?

Last updated: 13 July 2026

In our updated market reports, you will find everything you need

The nuclear fusion market now includes reactor developers, fuel-cycle specialists, magnet manufacturers, isotope producers, and fusion propulsion companies.

This ranking compares 98 nuclear fusion startups using their latest reported or estimated valuations.

We update this list every month as new funding rounds, transactions, public filings, and company disclosures become available.

A quick summary table

Metric	Value
Most valuable nuclear fusion startup	Helion Energy, $15.5B
Second most valuable nuclear fusion startup	Commonwealth Fusion Systems, $8.3B midpoint
Median nuclear fusion startup valuation	Approximately $59M
Share of nuclear fusion valuation captured by the top 10	Approximately 74%
Top nuclear fusion startup valuation vs. median	Approximately 264 times
Median nuclear fusion valuation-to-capital-raised ratio	Approximately 4.3 times
Nuclear fusion startups valued at $1B+	15 startups, based on valuation midpoints

Top startups in the nuclear fusion market ranked by valuation

Here is an updated table that ranks the top startups in the nuclear fusion market based on their latest reported or estimated valuations.

#	Startup Name	What They Do	Current Valuation ($)	Valuation Confidence Level	Valuation Type	Evidence Status	Total Funding ($)	Funding Confidence Level
1	Helion Energy	Pulsed magnetic fusion power	$15.5B	Full Confidence	Announced Private Round Valuation	Observed	$1.5B	Strong Confidence
2	Commonwealth Fusion Systems	Tokamak fusion power plants	$5.8B–$10.8B	Strong Confidence	Implied Valuation from Raise	Implied	$2.8B	Strong Confidence
3	TAE Technologies	Aneutronic FRC fusion power	$6.0B	Strong Confidence	IPO or Listing Range Valuation	Observed	$1.4B	Partial Confidence
4	Inertia	Laser inertial fusion power plants	$2.3B–$3.8B	Strong Confidence	Implied Valuation from Raise	Implied	$450M	Strong Confidence
5	Proxima Fusion	Stellarator fusion power plants	$2.8B	Full Confidence	Announced Private Round Valuation	Observed	$198M	Strong Confidence
6	SHINE Technologies	Fusion isotopes and fuel recycling	$1.8B–$3.0B	Strong Confidence	Implied Valuation from Raise	Implied	$740M	Partial Confidence
7	Neo Fusion	Chinese tokamak fusion developer	$2.0B–$2.7B	Partial Confidence	Proxy-Based Estimate	Estimated	$2.0B	Partial Confidence
8	China Fusion Energy	State fusion commercialization platform	$2.1B–$2.5B	Strong Confidence	Proxy-Based Estimate	Estimated	$1.6B	Strong Confidence
9	Pacific Fusion	Pulsed magnetic fusion systems	$1.5B–$2.5B	Partial Confidence	Comparables-Based Estimate	Estimated	$900M	Strong Confidence
10	Focused Energy	Laser-driven inertial fusion	$1.3B–$1.8B	Strong Confidence	Implied Valuation from Raise	Implied	$266M	Strong Confidence
11	Zap Energy	Sheared-flow Z-pinch fusion	$950M–$1.2B	Partial Confidence	Comparables-Based Estimate	Estimated	$330M	Strong Confidence
12	Startorus Fusion	Spherical tokamak fusion systems	$1.0B–$1.1B	Strong Confidence	Announced Private Round Valuation	Observed	>$291M	Partial Confidence
13	Type One Energy	Stellarator fusion power plants	$900M–$1.2B	Strong Confidence	Active Raise Valuation	Observed	$170M	Strong Confidence
14	Energy Singularity	High-field superconducting tokamak	$800M–$1.2B	Strong Confidence	Implied Valuation from Raise	Implied	$261M	Strong Confidence
15	Tokamak Energy	Spherical tokamaks and HTS magnets	$800M–$1.2B	Partial Confidence	Implied Valuation from Raise	Implied	$275M	Partial Confidence
16	General Fusion	Magnetized target fusion power	$900M–$1.0B	Strong Confidence	IPO or Listing Range Valuation	Observed	$305M	Partial Confidence
17	Thea Energy	Planar-coil stellarator power plants	$700M–$1.0B	Strong Confidence	Implied Valuation from Raise	Implied	$130M	Strong Confidence
18	Marvel Fusion	Laser-driven fusion power systems	$650M–$900M	Strong Confidence	Implied Valuation from Raise	Implied	$184M	Strong Confidence
19	ENN	Proton-boron spherical tokamak research	$500M–$900M	Low Confidence	Proxy-Based Estimate	Estimated	$400M	Partial Confidence
20	Kyoto Fusioneering	Fusion plant engineering systems	$550M–$850M	Strong Confidence	Implied Valuation from Raise	Implied	$121M	Strong Confidence
21	SunUp Fusion	Compact helium-three fusion plants	$500M–$750M	Partial Confidence	Implied Valuation from Raise	Implied	$115M+	Partial Confidence
22	Xcimer Energy	Laser-driven inertial fusion	$450M–$750M	Partial Confidence	Implied Valuation from Raise	Implied	$100M	Partial Confidence
23	NovaFusionX	Compact FRC fusion reactors	$450M–$700M	Strong Confidence	Implied Valuation from Raise	Implied	$176M	Strong Confidence
24	Star Energy Xuanlight	Field-reversed configuration fusion	$370M–$610M	Partial Confidence	Implied Valuation from Raise	Implied	$73M	Low Confidence
25	Longview Fusion	Laser fusion power plants	$300M–$600M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
26	Beta Fusion	Chinese tokamak fusion startup	$150M–$350M	Partial Confidence	Implied Valuation from Raise	Implied	Not provided	Partial Confidence
27	Alpha Ring	Micro-fusion energy systems	$180M–$350M	Partial Confidence	Comparables-Based Estimate	Estimated	$53M	Partial Confidence
28	Renaissance Fusion	Simplified stellarator fusion reactors	$190M–$300M	Partial Confidence	Implied Valuation from Raise	Implied	$50M	Partial Confidence
29	First Light Fusion	Projectile-driven inertial fusion technology	$190M–$280M	Partial Confidence	Comparables-Based Estimate	Estimated	$135M	Full Confidence
30	Fuse Energy Technologies	Pulsed-power MagLIF fusion systems	$200M–$260M	Strong Confidence	Announced Private Round Valuation	Observed	$32M	Full Confidence
31	Realta Fusion	Compact magnetic mirror fusion	$180M–$280M	Strong Confidence	Implied Valuation from Raise	Implied	$45M	Strong Confidence
32	Astral Systems	Fusion medical isotope reactors	$155M–$260M	Strong Confidence	Implied Valuation from Raise	Implied	$37M	Strong Confidence
33	Avalanche Energy	Compact micro-fusion reactors	$145M–$240M	Strong Confidence	Implied Valuation from Raise	Implied	$74M	Strong Confidence
34	MiRESSO	Fusion beryllium supply chain	$140M–$220M	Strong Confidence	Implied Valuation from Raise	Implied	$30M	Full Confidence
35	Blue Laser Fusion	Laser-driven inertial fusion	$120M–$230M	Partial Confidence	Implied Valuation from Raise	Implied	$38M	Full Confidence
36	Faraday 1867	Manufactures superconducting fusion tape	$120M–$220M	Partial Confidence	Revenue or ARR Multiple Estimate	Estimated	$0	Low Confidence
37	Helical Fusion	Helical stellarator fusion power	$115M–$210M	Partial Confidence	Implied Valuation from Raise	Implied	$44M	Strong Confidence
38	Acceleron Fusion	Muon-catalyzed fusion energy	$120M–$200M	Partial Confidence	Implied Valuation from Raise	Implied	$24M	Full Confidence
39	SuperMag New Energy	Builds high-field fusion magnets	$110M–$190M	Strong Confidence	Implied Valuation from Raise	Implied	>$56M	Partial Confidence
40	Xeonova	Field-reversed configuration reactors	$90M–$180M	Partial Confidence	Implied Valuation from Raise	Implied	$28M+	Partial Confidence
41	nT-Tao	Compact fusion power systems	$90M–$150M	Partial Confidence	Comparables-Based Estimate	Estimated	$28M	Strong Confidence
42	Interlune	Extracts lunar helium-three resources	$90M–$140M	Partial Confidence	Implied Valuation from Raise	Estimated	$23M	Strong Confidence
43	EX-Fusion	Laser fusion power systems	$90M–$140M	Partial Confidence	Comparables-Based Estimate	Estimated	$42M	Partial Confidence
44	LPP Fusion	Dense plasma focus fusion	$100M–$115M	Strong Confidence	Active Raise Valuation	Observed	$12M	Partial Confidence
45	OpenStar Technologies	Levitated dipole fusion reactors	$70M–$130M	Partial Confidence	Comparables-Based Estimate	Estimated	$6M	Partial Confidence
46	LINEA Innovations	Proton-boron aneutronic fusion	$60M–$100M	Partial Confidence	Implied Valuation from Raise	Implied	$12M	Full Confidence
47	Novatron Fusion	Magnetic mirror fusion concept	$60M–$95M	Partial Confidence	Implied Valuation from Raise	Implied	$20M	Strong Confidence
48	YAN Fusion	Stellarator superconducting magnet systems	$55M–$95M	Partial Confidence	Implied Valuation from Raise	Implied	$14M	Partial Confidence
49	High Temperature Superconductors	Manufactures ReBCO superconducting tape	$40M–$80M	Low Confidence	Comparables-Based Estimate	Estimated	$0	Low Confidence
50	Fusion Fuel Cycles	Tritium fuel-cycle testing systems	$35M–$80M	Low Confidence	Proxy-Based Estimate	Estimated	$20M	Low Confidence
51	Hexium	Laser isotope enrichment systems	$40M–$70M	Partial Confidence	Implied Valuation from Raise	Implied	$10M	Strong Confidence
52	Starlight Engine	Advanced superconducting tokamak project	$25M–$70M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
53	Gauss Fusion	Stellarator fusion power plants	$35M–$60M	Partial Confidence	Implied Valuation from Raise	Implied	$9M	Strong Confidence
54	SuNAM	Produces superconducting HTS wire	$44M	Full Confidence	Public Market Cap	Observed	$14M	Partial Confidence
55	Pranos Fusion	Compact tokamak fusion systems	$28M–$45M	Strong Confidence	Implied Valuation from Raise	Implied	$7M	Strong Confidence
56	MIFTI	Pulsed-power fusion reactors	$20M–$45M	Low Confidence	Comparables-Based Estimate	Estimated	$0	Low Confidence
57	Kronos Fusion Energy	Aneutronic compact fusion generators	$24M–$40M	Low Confidence	Implied Valuation from Raise	Implied	$6M	Low Confidence
58	Blue Star Fusion	Stellarator fusion technology	$15M–$40M	Low Confidence	Proxy-Based Estimate	Estimated	Not provided	Low Confidence
59	Stellarex	Simplified stellarator fusion systems	$15M–$40M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
60	Marathon Fusion	Fusion fuel processing systems	$22M–$35M	Partial Confidence	Implied Valuation from Raise	Implied	$11M	Partial Confidence
61	Maritime Fusion	Ship-based fusion reactors	$21M–$34M	Strong Confidence	Implied Valuation from Raise	Implied	$5M	Full Confidence
62	Oxford Sigma	Engineers advanced fusion materials	$20M–$35M	Partial Confidence	Comparables-Based Estimate	Estimated	$0	Full Confidence
63	Hanhai Energy	Linear FRC fusion devices	$18M–$35M	Partial Confidence	Implied Valuation from Raise	Implied	~$7M+	Partial Confidence
64	Pulsar Fusion	Fusion propulsion systems	$15M–$35M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
65	Helicity Space	Fusion propulsion for spacecraft	$15M–$30M	Partial Confidence	Comparables-Based Estimate	Estimated	$5M	Strong Confidence
66	ExoFusion	Fusion divertors and plasma engineering	$15M–$30M	Low Confidence	Comparables-Based Estimate	Estimated	<$1M	Low Confidence
67	HTS-110	Manufactures cryogen-free superconducting magnets	$15M–$30M	Partial Confidence	Comparables-Based Estimate	Estimated	$0	Partial Confidence
68	Molten Salt Solutions	Enriches lithium isotopes	$15M–$25M	Strong Confidence	Implied Valuation from Raise	Implied	$3M	Full Confidence
69	HB11 Energy	Hydrogen-boron laser fusion	$12M–$25M	Low Confidence	Comparables-Based Estimate	Estimated	$4M	Strong Confidence
70	Princeton Fusion Systems	Space fusion propulsion systems	$10M–$25M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
71	Cambridge Heavy Industries	Laser tritium production	$8M–$25M	Low Confidence	Proxy-Based Estimate	Estimated	Not provided	Low Confidence
72	Terra Fusion	Centrifugal magnetic mirror fusion	$8M–$25M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
73	Firefly Fusion	Compact negative-triangularity tokamak	$8M–$20M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
74	NearStar Fusion	Pulsed magneto-inertial fusion	$8M–$18M	Low Confidence	Comparables-Based Estimate	Estimated	$0	Low Confidence
75	Horne Technologies	Hybrid compact fusion reactors	$8M–$15M	Low Confidence	Proxy-Based Estimate	Estimated	$3M	Low Confidence
76	Smart Fusion Energy	Compact modular tokamak fusion	$8M–$13M	Strong Confidence	Implied Valuation from Raise	Implied	$2M	Strong Confidence
77	HyperJet Fusion	Plasma-jet magneto-inertial fusion	$5M–$12M	Low Confidence	Proxy-Based Estimate	Estimated	$2M	Partial Confidence
78	Jupiter Volta	Multipurpose stabilized plasma systems	$4M–$12M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Full Confidence
79	LaserFusionX	Deep-ultraviolet laser fusion	$4M–$12M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Full Confidence
80	PolyKrom Energy	Laser inertial fusion commercialization	$5M–$12M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
81	Zephyr Fusion	Orbital fusion power systems	$6M–$10M	Strong Confidence	Implied Valuation from Raise	Implied	$1M	Full Confidence
82	Innoven Energy	Krypton-fluoride laser fusion	$3M–$10M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Full Confidence
83	Liberty Fusion	Plasma-jet magneto-inertial fusion	$3M–$9M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Full Confidence
84	Ciral Fusion	Impact-initiated modular fusion	$3M–$8M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
85	LiSTie Corporation	Lithium recovery for fusion	$4M–$8M	Partial Confidence	Implied Valuation from Raise	Implied	$1M	Partial Confidence
86	Mirror Fusion	Stabilized magnetic mirror fusion	$3M–$8M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
87	Equilibria Power	Controls high-voltage solid-state power	$3M–$8M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
88	DANTE Fusion	Commercial fusion neutron sources	$4M–$7M	Partial Confidence	Implied Valuation from Raise	Implied	$1M	Partial Confidence
89	Eos Atomics	Neutral-beam fusion heating systems	$4M–$7M	Partial Confidence	Implied Valuation from Raise	Implied	$1M	Low Confidence
90	Deutelio	Poloidal plasma confinement technology	$3M–$7M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
91	Electric Fusion Systems	Aneutronic electric fusion systems	$2M–$6M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
92	Gridfire	Economically scalable fusion power	$2M–$6M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Strong Confidence
93	Atled Engineering	Models superconducting fusion magnets	$2M–$6M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Full Confidence
94	ASPL Fusion	Plasma neutron applications	$2M–$5M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
95	Crossfield Fusion	Fusion fuel-cycle reactor technology	$2M–$5M	Low Confidence	Proxy-Based Estimate	Estimated	$0.4M	Strong Confidence
96	GenF	Laser inertial fusion systems	$1M–$5M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
97	Atlas Fusion	AI Z-pinch fusion	$2M–$4M	Low Confidence	Implied Valuation from Raise	Implied	$0.5M	Low Confidence
98	Meranti Research Labs	Parker-effect plasma confinement	$1M–$4M	Low Confidence	Proxy-Based Estimate	Estimated	$0	Low Confidence
99	Anubal Fusion	Proton-boron inertial fusion	$1M–$2M	Strong Confidence	Implied Valuation from Raise	Implied	$0.3M	Strong Confidence

Key valuation trends in the nuclear fusion market

Insights

Helion Energy alone represents about 22% of the combined midpoint valuation in this ranking. This shows how strongly nuclear fusion investors currently reward credible paths to commercial electricity.
The ten most valuable nuclear fusion startups capture approximately 74% of the market’s total estimated valuation, even though the ranking contains almost 100 companies.
Proxima Fusion has a valuation-to-funding ratio above 14 times. The figure is unusually high for a capital-intensive reactor developer and reflects strong investor interest in stellarator technology.
Stellarator developers Proxima Fusion, Type One Energy, Thea Energy, and Helical Fusion have a combined midpoint valuation of about $4.2B from approximately $542M of disclosed capital.
Inertia, Focused Energy, Marvel Fusion, Astral Systems, and Fuse Energy Technologies have a combined midpoint valuation near $5.7B, showing that inertial fusion extends well beyond one flagship company.
Kyoto Fusioneering has a midpoint valuation near $700M despite focusing on fusion plant engineering. Nuclear fusion suppliers can therefore reach reactor-scale valuations without developing an entire power plant.
The nuclear fusion valuation distribution is sharply concentrated. Fifteen companies have midpoint valuations of at least $1B, while more than half of the companies remain below approximately $59M.
The leading nuclear fusion startups use tokamaks, stellarators, inertial systems, magnetic mirrors, Z-pinches, and field-reversed configurations. Investment has not yet converged around one dominant reactor design.

A few word about our methodology

As you can see, we built a database that ranks nuclear fusion startups based on their current valuation.

Estimating nuclear fusion startup valuations is not always straightforward. Many companies do not publicly disclose their valuation, and the available information can vary widely depending on the company and its stage.

To build this ranking, we applied a structured valuation methodology and cross-checked information across multiple reliable sources.

Whenever possible, we relied on direct disclosures. These include announced valuations from completed funding rounds, public filings for listed companies, or official acquisition prices.

When a nuclear fusion company is publicly listed, we use its current market capitalization as the reference valuation.

If a company was acquired and no independent valuation can reasonably be estimated today, we use the acquisition price as the main reference point.

When a nuclear fusion startup recently raised capital but the valuation was not disclosed, we estimate the implied valuation using typical dilution levels for that stage of fundraising.

In some cases, we estimate valuations using operating metrics such as revenue, contracted projects, commercial partnerships, or customer traction. We combine these signals with valuation multiples from comparable companies.

Commercial revenue remains limited across much of the nuclear fusion market. For this reason, technical progress, demonstrated plasma performance, engineering milestones, strategic investors, and government support can carry more weight than current revenue.

When direct financial data is not available, we may rely on carefully selected comparable startups and other signals such as hiring growth, investor quality, research progress, intellectual property, or product traction.

We treat reactor developers differently from suppliers, isotope companies, propulsion ventures, and fuel-cycle specialists. Each category has different capital requirements, technical risks, development timelines, and potential revenue models.

All estimates follow a strict evidence hierarchy. Recent funding rounds with announced valuations carry the most weight, followed by strong operating metrics and comparable company analysis.

We also carefully evaluate the age of every data point. Recent information carries more weight, while older data is treated cautiously and adjusted conservatively when necessary.

Whenever information is uncertain or incomplete, we clearly distinguish between confirmed facts and reasonable inferences.

Because valuation data is not always fully public, each nuclear fusion startup in the ranking is assigned a confidence level based on the reliability, recency, and consistency of the available evidence.

Full confidence means the valuation is supported by strong and recent evidence. Strong confidence means the estimate is well supported but includes minor inference. Partial confidence means the estimate relies more heavily on indirect signals. Low confidence means available information is limited or inconsistent.

When confidence is lower, we take a more conservative approach by widening the valuation range. This helps reflect the uncertainty and increases the probability that the true valuation falls within the estimated range.

In a world where LLMs hallucinate and unreliable information is everywhere, our goal is simple: provide data you can trust.

If you want the full detail on a specific valuation estimate, feel free to contact us and we will gladly explain.

Finally, know that we update the dataset once per month, so come back here if you need fresh information.

Related blog posts

- What are the key fundraising trends in the nuclear fusion market?

- The most heavily funded startups in the nuclear fusion market

- What does funding activity look like in the nuclear fusion market?

- A complete overview of funding deals in the nuclear fusion market

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