Commonwealth Fusion Systems Valuation, Funding & Investors

Commonwealth Fusion Systems is valued at $3.4B as of August 2025.

Last Commonwealth Fusion Systems valuation

$3.4B

Series B · Aug 2025

Last Commonwealth Fusion Systems funding round

$1B

Undisclosed stage · Jul 2026

Cumulative funding Commonwealth Fusion Systems raised

$3.9B

across 5 funding rounds

Key investors in Commonwealth Fusion Systems

  • Khosla Ventures
  • Tiger Global
  • Breakthrough Energy Ventures
  • Future Ventures
  • Temasek
  • Alphabet

Commonwealth Fusion Systems Overview

About Commonwealth Fusion Systems

Devens, Massachusetts-headquartered Commonwealth Fusion Systems pioneers compact tokamak fusion reactors powered by high-temperature superconducting magnets. The company constructs SPARC, a six-meter-wide demonstration tokamak scheduled for net energy production by 2025 at its Devens site, which serves as a prototype for ARC, a 200-400 megawatt pilot plant intended for grid connection in New Hampshire during the early 2030s. CFS produces its proprietary magnets in-house at a dedicated factory opened in 2021 and collaborates closely with the MIT Plasma Science and Fusion Center on plasma physics advancements. Key technologies include the VIPER cable design enabling 20-tesla magnetic fields essential for plasma confinement. Founded in 2018 as an MIT spinout, CFS advances commercial fusion through rigorous peer-reviewed engineering.


Founded

2017

HQ

United StatesUnited States

Website

cfs.energy

Status

Privately held

Customer focus

B2B

Revenue model

Product sales

Valuation

$3.4B (Aug 2025)

Commonwealth Fusion Systems Valuation

Commonwealth Fusion Systems is currently valued at $3.4B, based on its Series B in August 2025.

The $863M round was led by Planet First Partners, with participation from Brevan Howard Asset Management, Future Ventures, Galaxy Interactive, Breakthrough Energy Ventures, Counterpoint Global and 6 other investors.

Commonwealth Fusion Systems valuation by funding round

Commonwealth Fusion Systems valuation by funding round
DateStageValuation
Aug 2025Series B$3.4B

Commonwealth Fusion Systems Funding History

Commonwealth Fusion Systems has raised a total of $3.9B across 5 funding rounds.

Commonwealth Fusion Systems' first fundraising round was a $115M Series A in June 2019. The most recent completed round was a $1B undisclosed-stage round in July 2026.

Commonwealth Fusion Systems funding rounds

Commonwealth Fusion Systems funding rounds
DateStageInvestorsRaisedValuationDeal Summary
Jul 2026Undisclosed stage-$1B-Commonwealth Fusion Systems raised USD 1000 million in additional equity financing on July 30, 2026, bringing total capital raised to USD 4000 million. The round was described as the largest fusion-energy funding round since CFS’s USD 1800 million round in 2021, and the investor base included pension funds, sovereign wealth funds, infrastructure funds, and industrial companies. The new capital is intended to accelerate CFS’s commercial path, with reporting indicating the funds are being directed toward ARC, the company’s planned commercial fusion power plant, after progress on its SPARC demonstration tokamak. CFS said the latest financing reflects its status as the best-funded fusion developer and represents about 30 percent of all capital raised in the fusion industry to date. Commonwealth Fusion Systems is a Massachusetts-based fusion company founded in 2018 as a spinout from MIT. It has raised capital from a broad mix of strategic and institutional backers, including major technology and energy-related investors, and is advancing SPARC as a demonstration system ahead of ARC as its first commercial power plant.
Aug 2025Series BPlanet First Partners (lead); Brevan Howard Asset Management; Future Ventures; Galaxy Interactive; Breakthrough Energy Ventures; Counterpoint Global; Khosla Ventures; HOF Capital; Lowercarbon Capital; Tiger Global; Gates Frontier Fund; Alphabet$863M$3.4BCommonwealth Fusion Systems (CFS), a fusion power company spun out from MIT, raised $863 million in a Series B2 funding round on August 27-28, 2025, from investors including Breakthrough Energy Ventures, Brevan Howard Asset Management, Counterpoint Global, Khosla Ventures, Lowercarbon Capital, Tiger Global, Future Ventures, Galaxy Interactive, Gates Frontier Fund, HOF Capital, and Google. This follows their $1.8 billion Series B in 2021, bringing total funding to nearly $3 billion, about one-third of all private fusion investment worldwide. The round was described as an up round and oversubscribed beyond the $800 million target. Funds will complete the SPARC fusion demonstration machine, over 65% done and expected to achieve net-positive energy soon, and advance the ARC power plant in Virginia, approved by regulators, aiming for grid connection in the early 2030s. CFS has a 200 MW offtake agreement with Google and partnerships like Dominion Energy. One source lists the post-money valuation at $3.4 billion. CFS leads private fusion efforts with high-field magnet technology for commercial fusion, targeting costs of $50 per megawatt-hour to compete with renewables amid rising energy demand from AI and data centers.
Dec 2021Series BTiger Global (lead)$1.8B-Commonwealth Fusion Systems (CFS), a fusion energy company developing SPARC (world’s first net-energy fusion machine) and ARC (commercial fusion power plant), closed a $1.8 billion Series B funding round on January 12, 2021, led by Tiger Global Management with participation from investors including Bill Gates, Coatue, DFJ Growth, Emerson Collective, Google, and others. The capital supports construction and operation of SPARC and initial work on ARC to advance commercial fusion power as a decarbonization solution. CFS positions fusion as a scalable clean energy technology, with this round highlighting investor confidence from energy, tech, and financial sectors.
May 2020Series ATemasek (lead)$84M-Commonwealth Fusion Systems (CFS), founded in 2018 and spun out from MIT, develops high-temperature superconducting (HTS) magnets to enable compact fusion energy systems, aiming to build SPARC, the world’s first net-energy-gain fusion machine, and ARC, the first commercial fusion power plant. On May 26, 2020, CFS raised $84 million in its Series A2 funding round led by Temasek Holdings, with participation from new investors Equinor and Devonshire Investors (affiliated with FMR LLC/Fidelity), plus existing backers like Breakthrough Energy Ventures, The Engine, ENI Next LLC, Future Ventures, Hostplus, Khosla Ventures, Moore Strategic Ventures, Safar Partners, Schooner Capital, and Starlight Ventures, bringing total funding over $200 million at that point. The capital supported acceleration of SPARC development, construction of new headquarters and manufacturing facilities in Devens, Massachusetts, expansion of fusion power plants and engineering services, and business development for HTS magnets with broader commercial applications. CEO Bob Mumgaard highlighted the round's significance amid challenges, underscoring a shift from public to private fusion efforts to combat climate change. CFS has since raised larger rounds, including $1.8 billion Series B in December 2021 led by Tiger Global with participation from Bill Gates, Google, Temasek, and others to build SPARC and start ARC, and $863 million Series B2 in August 2025, reaching nearly $3 billion total funding and positioning CFS as the leading private fusion company.
Jun 2019Series ABreakthrough Energy Ventures (lead); Future Ventures; The Engine; Starlight Ventures; Lowercase Capital; Schooner Capital; Khosla Ventures; Safar Partners; Eni Next; Moore Strategic Ventures$115M-Commonwealth Fusion Systems (CFS), an MIT spinoff founded in 2018, focuses on commercializing fusion energy through high-temperature superconducting magnets and developing SPARC, the world's first net-energy-gain fusion system, in collaboration with MIT's Plasma Science and Fusion Center. On June 27, 2019, CFS closed its $115 million Series A round led by Breakthrough Energy Ventures, with participation from Eni Next, Future Ventures, Khosla Ventures, Lowercase Capital, Moore Strategic Ventures, Safar Partners, Schooner Capital, Starlight Ventures, The Engine, and others. At the time of the Series A, CFS had grown to 25 employees and was on track with its projects aimed at addressing climate change through carbon-free energy. The funds supported development of fusion power plants, fusion engineering services, HTS magnets with commercial applications beyond fusion, SPARC construction, headquarters, and manufacturing facilities. CFS positioned itself as ready to harness fusion power, with investors like Vinod Khosla and Steve Jurvetson citing its proven science and engineering as the best path to commercial fusion.

Who has invested in Commonwealth Fusion Systems?

20 investors have backed Commonwealth Fusion Systems across its funding rounds, including Khosla Ventures, Tiger Global, Breakthrough Energy Ventures, Future Ventures, Temasek and Alphabet.

Lead investors include Planet First Partners, Tiger Global, Temasek and Breakthrough Energy Ventures.


Commonwealth Fusion Systems Investors

Investors in Commonwealth Fusion Systems by funding rounds participated
InvestorHQRoundsRoleFirst check
Future VenturesUnited StatesSan Francisco, CA2ParticipantJun 2019
Breakthrough Energy VenturesFranceParis2LeadJun 2019
Khosla VenturesUnited StatesSan Francisco, CA2ParticipantJun 2019
Tiger GlobalUnited StatesNew York City, NY2LeadDec 2021
TemasekSingaporeSingapore1LeadMay 2020
Brevan Howard Asset ManagementUnited KingdomLondon1ParticipantAug 2025
Galaxy InteractiveUnited StatesNew York City, NY1ParticipantAug 2025
The EngineUnited StatesUnited States1ParticipantJun 2019
Starlight VenturesUnited StatesMiami, FL1ParticipantJun 2019
Lowercase CapitalUnited StatesSan Francisco, CA1ParticipantJun 2019
Counterpoint GlobalUnited StatesNew York City, NY1ParticipantAug 2025
Schooner CapitalUnited StatesBoston, MA1ParticipantJun 2019
Safar PartnersUnited StatesUnited States1ParticipantJun 2019

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Commonwealth Fusion Systems Competitors

Commonwealth Fusion Systems competitors include listed companies like Chugoku Electric Power, Energy Fuels, ERG and Drax Group, and private ones like Proxima Fusion and Enel Green Power Hellas.

Public and private companies comparable to Commonwealth Fusion Systems
CompanyHQStatusRevenueEBITDAValuationRevenue Multiple
Chugoku Electric PowerJapanJapanPublicly listed$9.3B$1.6B$2.6B2.2x
Energy FuelsUnited StatesUnited StatesPublicly listed$66M($84M)$3.2B25.6x
ERGItalyItalyPublicly listed$856M$523M$3.7B6.8x
Drax GroupUnited KingdomUnited KingdomPublicly listed$7.2B$659M$3.7B0.7x
Proxima FusionGermanyMunichPrivate--$2.7B-
Enel Green Power HellasGreeceAthensPrivate--$2.3B-

Commonwealth Fusion Systems Public Comps

Commonwealth Fusion Systems is still privately-owned, but its public comps include Baytex Energy, Alliance Res Partners, Paramount Resources, Shanghai Petrochemical, Guangzhou Development Group, ALDREES Petroleum, Antarchile, Greencoat UK Wind, Peyto and Energa.

Last FYEV/RevenueEV/EBITDA
RevenueEBITDALast FYLTM2027ELast FYLTM2027E
Baytex Energy$1.2B$915M2.5x1.8x3.3x3.7x
Alliance Res Partners$2.2B$672M1.8x1.7x5.7x5.2x
Paramount Resources$729M$277M4.3x4.6x11.3x5.3x
Shanghai Petrochemical$11B$23M0.3x0.3x134.8x30.2x
Guangzhou Development Group$7.6B$984M1.1x1.0x8.3x-
ALDREES Petroleum$6.9B$332M0.7x0.6x13.5x13.1x
Antarchile$30B$2.8B0.7x-7.4x-
Greencoat UK Wind($249M)-(22.2x)12.5x--

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Common questions about Commonwealth Fusion Systems

When was Commonwealth Fusion Systems founded?Commonwealth Fusion Systems was founded in 2017.
Where is Commonwealth Fusion Systems headquartered?Commonwealth Fusion Systems is headquartered in United States.
Is Commonwealth Fusion Systems publicly listed?No, Commonwealth Fusion Systems is a private, VC-backed company.
What is Commonwealth Fusion Systems' valuation?Commonwealth Fusion Systems was last valued at $3.4B in its Series B in August 2025.
How much funding has Commonwealth Fusion Systems raised?Commonwealth Fusion Systems has raised $3.9B across 5 funding rounds.
What was Commonwealth Fusion Systems' last funding round?Commonwealth Fusion Systems' last funding round was a $1B undisclosed-stage round in July 2026.
Who are Commonwealth Fusion Systems' investors?Commonwealth Fusion Systems' investors include Future Ventures, Breakthrough Energy Ventures, Khosla Ventures, Tiger Global, Temasek, Brevan Howard Asset Management, Galaxy Interactive, The Engine, Starlight Ventures, Lowercase Capital and 10 others.
Which companies are comparable to Commonwealth Fusion Systems?Companies comparable to Commonwealth Fusion Systems include Chugoku Electric Power, Energy Fuels, ERG, Drax Group, Proxima Fusion and Enel Green Power Hellas.

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