Fusion startups have raised a record $4.0B in 2026
Five of the ten biggest fusion rounds ever closed this year. Dealroom maps 75 private fusion companies and ranks the ten with the most momentum.
By Boris Bavinck and Dealroom Next-Gen API · Dealroom maps 75 private fusion companies, from tokamaks and stellarators to laser fusion and the suppliers of fuel and parts. Together they have raised $13.9B.
The landscape
Tokamaks and stellarators use magnets to hold the plasma; pulsed and laser designs compress fuel in short bursts. The map groups every company by approach.
2026 is fusion’s biggest year
Fusion startups have raised $4.0B in venture funding so far this year, above the $2.9B of 2021. There were 11 rounds of $100M or more, against 6 in 2021. US companies raised 59% of this year’s total; China ($824M) and Germany ($692M) followed.
Fusion startups have raised a record $4.0B in 2026
Venture funding raised by 75 private fusion companies · rounds of $100M or more below each year
The biggest rounds
Commonwealth Fusion’s $1.0B round in July is the second-largest in the sector, after its own $1.8B in 2021. Helion, Proxima Fusion, Inertia and ENN Fusion each raised $300M or more this year.
Five of the top 10 nuclear fusion funding rounds of all time have happened in 2026
Largest venture rounds raised by private fusion companies · 2026
- 1Series B · Dec 2021 · United States$1.8B
- 2Equity round · Jul 2026 · United States$1.0B
- 3Series A · Oct 2024 · United States$900M
- 4Series B2 · Aug 2025 · United States$863M
- 5Series E · Nov 2021 · United States$500M
- 6Series G · Jun 2026 · United States$465M
- 7Series B · Jul 2026 · Germany$452M
- 8Series A · Feb 2026 · United States$450M
- 9Series F · Jan 2025 · United States$425M
- 10ENN FusionEarly VC · Jul 2026 · China$300M
The hottest startups
Helion, Focused Energy and Proxima Fusion have the highest Signal. 4 of the top ten, Pacific Fusion, Realta Fusion, Marvel Fusion and Xcimer Energy, have not raised in 2026. Commonwealth Fusion, the most-funded company, ranks 33rd.
The ten fusion startups with the highest Dealroom Signal
Signal is Dealroom’s 0 to 100 score of a company’s momentum · private companies only
- 1Pulsed and magneto-inertial · United States97$1.5Braised+51%headcount, 1 yr$465M in 2026
- 2Laser and inertial · Germany96$327Mraised+100%headcount, 1 yr$240M in 2026
- 3Stellarators · Germany96$651Mraised+52%headcount, 1 yr$452M in 2026
- 4Pulsed and magneto-inertial · United States96$900Mraised+52%headcount, 1 yrLast: Oct 2024, $900M
- 5Laser and inertial · United States95$450Mraised+450%headcount, 1 yr$450M in 2026
- 6Isotopes, neutrons and space · United States95$1.1Braised+36%headcount, 1 yr$240M in 2026
- 7Other magnetic · United States94$48Mraised+81%headcount, 1 yrLast: May 2025, $36M
- 8Type One EnergyStellarators · United States94$170Mraised+45%headcount, 1 yr$87M in 2026
- 9Marvel FusionLaser and inertial · Germany94$167Mraised+37%headcount, 1 yrLast: Mar 2025, $55M
- 10Xcimer EnergyLaser and inertial · United States93$118Mraised+53%headcount, 1 yrLast: Jun 2024, $100M
What to watch
- Commonwealth Fusion’s SPARC machine, due to make its first plasma in 2027.
- Helion’s plant for Microsoft, due in 2028.
- TAE’s merger with Trump Media and General Fusion’s Nasdaq listing, the first fusion companies on public markets.
- New rounds for the top-ten companies that have not raised this year.
Research notes: cohort, method and sources
Cohort. Dealroom has no single fusion tag that covers the whole sector. The 75 companies were found with semantic searches (nuclear fusion energy, fusion power plant, tokamak, stellarator, inertial confinement fusion, magnetized target fusion, aneutronic fusion, tritium breeding, superconducting magnets for fusion) and the roster of the Dealroom market map of nuclear fusion startups (list 25184), then screened by hand. Removed: companies that only use the word fusion (data fusion, fusion splicing), general superconductor and laser makers, quantum computing, low-energy nuclear reactions and other unproven concepts, research institutes and state programmes (UKIFS), and General Atomics. Shaanxi Xinghuan Energy Technology is the legal entity of Startorus Fusion and is counted once. Segments: tokamaks (10), other magnetic: frc, mirror, dipole (12), stellarators (11), pulsed and magneto-inertial (10), laser and inertial (12), muon-catalysed (2), fuel cycle and components (12), isotopes, neutrons and space (6).
Funding. Venture rounds (rounds Dealroom marks as VC) from companyFundingRounds, pulled 6 October 2026. Grants and government programmes are not included. General Fusion (listed on Nasdaq through a SPAC in 2026) and TAE Technologies (merging with Trump Media & Technology Group) count up to their listing; they are left out of the Signal ranking, which covers private companies only. Funding totals on the map include all round types.
Signal. Dealroom Signal is a 0 to 100 score of a company’s momentum. Coverage is weaker for Chinese companies, which score lower than their funding suggests (Startorus Fusion 22, Neo Fusion 32); ENN Fusion has no score yet.
Comparison. The Fusion Industry Association counts $14.24B raised by fusion companies to July 2026 (Global Fusion Industry report 2026), against $13.9B for the 75 companies here. SPARC and Helion dates: company announcements. TAE and Trump Media: merger announced December 2025. Dealroom data as of 2026-10-06.