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Commonwealth Fusion Systems

Commonwealth Fusion Systems

Private
Devens, MassachusettsEnergy & Sustainabilityhttps://cfs.energy/

Last Round

VC Round

Jul 30, 2026

Est. Valuation

$5B

Total Funding Raised

$2.91B

Momentum

Top 5%

of companies Caplight tracks

Company Overview

Commonwealth Fusion Systems is an energy technology company that designs and constructs fusion machines to deliver clean, limitless fusion energy.

Sector

Energy & Sustainability

Verticals

Renewable Energy, Advanced Materials

Business Model

B2B

Customer Profile

Revenue Share, Services & Consulting, Hardware Sales

AI Layer

Application

Keywords

fusion energyfusion powerhigh-temperature superconducting magnetsHTS magnetstokamakclean energybaseload powerdigital twinnet energy gainpower purchase agreementPPAfusion startupdeep techclimate techcommercial fusion

Historical Pricing

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Caplight Momentum Score

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Commonwealth Fusion Systems Comparables

Compare Commonwealth Fusion Systems with similar companies based on industry and business-model similarity.

Commonwealth Fusion Systems comparables — related companies by embedding similarity
CompanySimilarityMarket Cap
TAE Technologies
85%
Helion
83%
Tokamak Energy
81%

Commonwealth Fusion Systems Funding Rounds

Historical fundraising activity

Data table
RoundDateAmount RaisedValuationInvestorsSources
VC RoundJul 30, 2026
Series B ExtensionAug 28, 2025
Series BDec 1, 2021
Series A ExtensionMay 26, 2020
Series AJun 27, 2019
Seed
Mar 9, 2018

Key People

Founding team and executive leadership

Robert Mumgaard

CEO

Executive Team

Lorence Kim

Chief Financial Officer

Executive Team

Commonwealth Fusion Systems Investors

Notable investors and investment history

Commonwealth Fusion Systems investors
InvestorRounds
One Madison GroupSeries B
MITSeries A Extension, Seed, Series A
Development Bank of JapanSeries B, Series B Extension
Fine Structure VenturesSeries A Extension, Series B
Fujikura Ltd.Series B, Series B Extension
TemasekSeries B, Series A Extension
Future VenturesSeries A Extension, Series B, Series A, Series B Extension

Market signals

Structured signals derived from secondary market and firmographic data.

  • Jul 30, 2026

    $1.0B round raised

  • Jul 27, 2026

    Monthly visitors increased 41% MoM.

Recent news

Latest coverage and updates

  • partners_withSep 10, 2026

    Commonwealth Fusion Systems LLC partnered with Hyundai Group on Sep 10th '26.

  • receives_financingAug 3, 2026

    Commonwealth Fusion Systems LLC received financing of $13.5M in Series A on Jul 1st '18.

  • is_developingJul 31, 2026

    Commonwealth Fusion Systems LLC is developing net-energy positive fusion device on Jul 31st '26.

  • is_developingJul 31, 2026

    Commonwealth Fusion Systems LLC is developing SPARC fusion demonstration machine on Jul 31st '26.

  • receives_financingJul 31, 2026

    Commonwealth Fusion Systems LLC was planning to receive financing of $1B in funding on Jul 31st '26.

Commonwealth Fusion Systems Filings

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Commonwealth Fusion Systems filings preview — column headings only; records require access
TypeDateAmount OfferedAmount SoldFilingPagesDownload

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Appears On

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Frequently Asked Questions

Common questions about Commonwealth Fusion Systems's valuation, stock price, and market status.

Is CFS a public or private company?

CFS is a private company.

What is the current stock price of CFS?

CFS is a private company with no public stock price. No recent secondary market data is available.

How much is CFS worth (valuation)?

CFS's valuation is estimated at $5.0B based on funding round data.

Can I buy CFS stock?

CFS shares may be available on secondary markets subject to transfer restrictions. Caplight facilitates secondary market transactions for accredited investors. Visit https://www.caplight.com to learn more.

When was CFS's last funding round?

CFS's most recent funding round was Series B Extension on December 1, 2021.

Who are the main investors in CFS?

Key investors in CFS include Temasek, Eni, Breakthrough Energy Ventures, Tiger Global Management.

Will CFS IPO soon?

No public IPO plans have been announced for CFS.

How can I track CFS secondary market activity?

Caplight tracks bids, offers, and trades for private companies. Visit https://www.caplight.com to monitor CFS's secondary market activity and sign up for updates.

Firmographic Details

HeadquartersDevens, Massachusetts
Employee Range925
Year Founded2018
Last FundingJul 30, 2026

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