Company: Commonwealth Fusion Systems Description: Private fusion-energy company building SPARC and ARC Founded: 2018 Headquarters: Devens, Massachusetts (117 Hospital Rd, Devens, MA 01434, United States) Employees / Headcount: 995 Website: cfs.energy Valuation (Aug 2025): $22.5B Total raised to date: $2.1B (Cumulative funding noted over $3.9B across 6 rounds) Company Tags: Fusion power, Clean energy, Tokamak, HTS magnets, MIT spinout Commonwealth Fusion Systems is a private fusion-energy company that develops compact tokamak power systems enabled by high-temperature superconducting magnets. It was founded in 2018 as a spin-out from MIT’s Plasma Science and Fusion Center, and its best-known programs are SPARC, its commercially relevant demonstration machine, and ARC, its planned grid-scale fusion power plant. CFS says it is building commercial fusion power plants and positions itself as the world’s largest and leading private fusion company. CFS has raised over $2 billion according to its company materials, and its publicly disclosed financings show a path from early seed funding to multibillion-dollar total capital raised. Its public footprint centers on Devens, Massachusetts, with the Chesterfield, Virginia ARC project as the next major deployment target. Legal Name: Commonwealth Fusion Systems LLC Website: cfs.energy Founded: 2018 Headcount: 995 HQ: Devens, Massachusetts Social: LinkedIn, X, Facebook Headquarters Address: 117 Hospital Rd, Devens, MA 01434, United States Offices: Devens, Massachusetts; former/alternate office location listed as Cambridge, Massachusetts at 148 Sidney Street - Bob Mumgaard: Co-founder & CEO - Brandon Sorbom: Co-founder & Chief Science Officer - Dan Brunner: Co-founder & Chief Technology Officer - Mitchell Goldstein: Chief Financial Officer - Alex Mozdzanowska: Chief People Officer - David Tressler: Chief Legal Officer - SPARC: Commercially relevant net-energy fusion demonstration machine. - ARC: Planned grid-scale fusion power plant for Chesterfield, Virginia. - Technology: Core technology page describing the HTS-magnet tokamak approach. - Devens campus: Massachusetts campus supporting development and manufacturing. - Commonwealth Fusion Systems announced $1 billion of additional equity financing, bringing its total capital raised to $4 billion. (Jul 2026) - Commonwealth Fusion Systems was named the first international partner in UKAEA’s LIBRTI program. (Jul 2026) - CFS described itself as a private fusion energy company building commercial fusion systems with high-temperature superconducting magnets (Aug 2026). - Fusion Energy News described CFS as the highest-funded private fusion company and said SPARC is designed for net energy gain followed by ARC in the early 2030s (Aug 2026). - CFS announced an $863 million Series B2 round to accelerate commercialization of fusion energy (Aug 2025). - CFS described its Devens campus as the site supporting development and manufacturing for SPARC and future work (Aug 2026). - CFS's technology page described the company's compact tokamak approach enabled by MIT-developed HTS magnet technology (Aug 2026). - CFS's careers page was actively recruiting for its fusion buildout (Aug 2026). Total funding: $3.9B+ across 6 rounds. Largest round: >$1.8B (Series B, Dec 2021). Investors: 71 (68 institutional, 3 angels). Latest valuation: $22.5B. Funding History: - Jul 2026: Equity financing (Growth stage), $1.0B raised. Investors include pension funds, sovereign wealth funds, infrastructure and industrial corporate partners. - Aug 2025: Series B2, $863M raised. Investors include Brevan Howard Macro Venture Fund, Counterpoint Global (Morgan Stanley), Stanley Druckenmiller, FFA Private Bank (Dubai) Ltd., Galaxy Interactive, Gigascale Capital, HOF Capital, Neva SGR, NVentures, Planet First Partners, Woori Venture Partners US, and others. - Dec 2021: Series B, >$1.8B raised. Lead: Tiger Global Management. Investors include Bill Gates, Coatue, DFJ Growth, Emerson Collective, Footprint Coalition, Google, JIMCO Technology Fund, John Doerr, JS Capital, Marc Benioff’s TIME Ventures, Senator Investment Group, a major university endowment, a pension plan, Breakthrough Energy Ventures, The Engine, Eni, Equinor Ventures, Fine Structure Ventures, Future Ventures, Hostplus, Khosla Ventures, Lowercarbon, Moore Strategic Ventures, Safar Partners, Schooner Capital, Soros Fund Management, Starlight Ventures, Temasek, and others. - May 2020: Series A2, $84M raised. Investors include Devonshire Investors, previous investors, Temasek, Equinor Ventures. - Jun 2019: Series A, $115M total raised. Investors include Breakthrough Energy Ventures, Khosla Ventures, Eni, and others. - 2018: Series B (Seed), $50M raised. Lead: Eni. Publicly Disclosed Financing by Year: - 2026: $1B - 2025: $863M - 2021: $1.8B - 2020: $84M - 2019: $115M - 2018: $50M - Total capital raised: more than $3 billion (company statement) - Total funding after May 2026 round: about $6.85 billion (2026 profile) - Estimated revenue: about $12 million (PrivatePulse) / about $5.6 million (SignalHire) Note: Publicly reported financial figures in the provided sources are limited to fundraising totals and employee counts; no company-reported revenue, ARR, or profitability figure appears. Total Investors: 71 total. Lead Investors: Eni (Series B, 2018), Tiger Global Management (Series B, Dec 2021). Key institutional, corporate, and angel investors include: Breakthrough Energy Ventures, Equinor Ventures, Khosla Ventures, Temasek, Bill Gates, Brevan Howard Macro Venture Fund, Coatue, Counterpoint Global (Morgan Stanley), DFJ Growth, Emerson Collective, FFA Private Bank (Dubai) Ltd., Fine Structure Ventures, Footprint Coalition, Future Ventures, Galaxy Interactive, Gigascale Capital, Google, HOF Capital, Hostplus, JIMCO Technology Fund, John Doerr, JS Capital, Lowercarbon, Marc Benioff’s TIME Ventures, Moore Strategic Ventures, Neva SGR, NVentures, Planet First Partners, Safar Partners, Schooner Capital, Senator Investment Group, Soros Fund Management, Stanley Druckenmiller, Starlight Ventures, The Engine, Woori Venture Partners US, Collaborative Fund, Development Bank of Japan, Eni Next, Eric Schmidt, Fujikura Company, Gates Frontier, George Soros, Hostplus Superannuation Fund, JERA, JGC Holdings Corporation, Kansai Electric Power, Lowercase Capital, Maria Zuber, MIT, Mitsubishi Corporation, Mitsui & Co., Ltd., Mitsui Fudosan, Mitsui OSK Lines, Morgan Stanley, NTT, NTT DOCOMO Ventures, OSTI, Resilience Reserve, Sumitomo Mitsui Banking Corporation, Sumitomo Mitsui Trust Bank, US Department of Energy, and Woori Ventures Partners. - 2026-03-31: 1,148 (Revelio Labs) - 2026-01-01: 1,064 (LinkedIn company page) - 2025-01-01: 1,000 (CFS Devens campus page / Wikipedia) - 2023-05-25: 500 (CFS YouTube / LinkedIn post) - 2022-12-31: 350 (Wikipedia) Core Technology Focus: - Tokamak fusion - High-temperature superconducting (HTS) magnets - SPARC demonstration device Source: company technology and engineering-facing materials. - Helion (Founded 2010, Series E, Redmond, United States): Commercial fusion power developer focused on deuterium-based magnetic fusion. - TAE Technologies (Founded 1998, Series G, Lake Forest, United States): Developer of field-reversed configuration fusion reactors. - General Fusion (Founded 2002, Series F, Burnaby, Canada): Magnetized target fusion developer building reactor systems for power generation. - Tokamak Energy (Founded 2009, Private, Abingdon, United Kingdom): Fusion company specializing in spherical tokamaks and superconductors. - Proxima Fusion (Founded 2023, Series A, Munich, Germany): Fusion power plant developer using quasi-isodynamic stellarators. - Xcimer Energy (Founded 2021, Series A, Redwood City, United States): Laser-based inertial fusion developer for commercial energy systems. - Zap Energy (Founded 2017, Series D, Everett, United States): Nuclear energy company developing Z-pinch fusion systems. - SHINE Technologies (Founded 2005, Series D, Janesville, United States): Fusion-tech company producing nuclear isotopes and related systems. - First Light Fusion (Founded 2011, Private, Oxford, United Kingdom): Inertial confinement fusion company using projectile-driven approaches. - Realta Fusion (Not stated, Stage not stated): Compact modular fusion energy developer listed as a CFS competitor. - Jun 10, 2026 (arstechnica.com): Commonwealth Fusion makes the physics case for its 400 MW reactor - Jan 8, 2026 (youtube.com): An update from Commonwealth Fusion Systems (January 2026) [video] - Sep 22, 2025 (technologyreview.com): An oil and gas giant signed a $1B deal with Commonwealth Fusion Systems - Sep 2, 2025 (cfs.energy): Commonwealth Fusion Systems Raises $863M to Commercialize Fusion Energy - Aug 30, 2025 (techcrunch.com): Nvidia, Google, and Bill Gates Help Commonwealth Fusion Systems Raise $863M - Jul 11, 2025 (reuters.com): Google strikes deal to buy fusion power from MIT spinoff Commonwealth Fusion Sys - Jul 4, 2025 (techcrunch.com): Google inks its first fusion power deal with Commonwealth Fusion Systems - Jun 30, 2025 (theregister.com): Google to buy fusion startup Commonwealth's power- if they can ever make it work - Dec 23, 2024 (cfs.energy): Commonwealth Fusion Systems to Build First Commercial Fusion Power Plant - Dec 18, 2024 (latitudemedia.com): Commonwealth Fusion Systems Announces Commercial Plant in Virginia - Dec 17, 2024 (news.mit.edu): Commonwealth Fusion Systems unveils plans for the first fusion power plant - Jun 24, 2024 (youtube.com): Virtual Tour of Commonwealth Fusion Systems' Sparc Facility [video] - Oct 5, 2022 (cfs.energy): Commonwealth Fusion Systems Raises $1.8B to Commercialize Fusion Energy - Dec 1, 2021 (wsj.com): Commonwealth Fusion Systems Raises $1.8B from Gates, Soros - Sep 10, 2021 (cfs.energy): Commonwealth Fusion Systems creates viable path to commercial fusion power - Jul 31, 2026 (finance.yahoo.com): Commonwealth Fusion Systems Raises Another $1 Billion as Work on Commercial Power Plant Continues - Jul 30, 2026 (techcrunch.com): When will fusion power startup Commonwealth Fusion Systems go public ? - Jul 30, 2026 (prnewswire.com): Commonwealth Fusion Systems Raises Another $1 Billion , Bringing Total Capital Raised to $4 Billion Q: When was Commonwealth Fusion Systems founded? A: Commonwealth Fusion Systems was founded in 2018. Q: Where is Commonwealth Fusion Systems headquartered? A: Commonwealth Fusion Systems is headquartered in Devens, Massachusetts, at 117 Hospital Rd, Devens, MA 01434, United States. Q: How much total capital has Commonwealth Fusion Systems raised? A: Commonwealth Fusion Systems has raised more than $3 billion since its founding. Q: What is Commonwealth Fusion Systems' latest valuation? A: A public latest valuation is not disclosed in the provided sources. Q: Who are Commonwealth Fusion Systems' main investors? A: Repeatedly cited major investors include Tiger Global, Breakthrough Energy Ventures, Eni, Temasek, Equinor, Khosla Ventures, Google, NVentures, Counterpoint Global, Stanley Druckenmiller, and a 12-company Japanese consortium led by Mitsui & Co. and Mitsubishi. Q: What is Commonwealth Fusion Systems' revenue or profitability? A: No public revenue or profitability figure appears in the provided sources.