Commonwealth Fusion Systems Raises $863 Million Series B2 Round to Accelerate the Commercialization of Fusion Energy

  • This round of capital is the largest raised among deep tech and energy companies since CFS’ $1.8 billion Series B round in 2021.
  • The almost $3 billion that CFS has raised to date is about one-third of the total capital invested in private fusion companies worldwide, solidifying its leadership of the fusion industry.
  • In recognition of the new category of energy technology that the company is creating, CFS expanded its global footprint by adding international investors from a widening range of sectors — from long-established fundamental investors, technology and industrial companies such as Counterpoint Global (Morgan Stanley) and Google, to hedge funds and leading individual investors such as Stanley Druckenmiller.

DEVENS, Mass., Aug. 28, 2025 /PRNewswire/ — Commonwealth Fusion Systems (CFS), the largest and leading private fusion company, today announced that it raised $863 million in a Series B2 fundraising round as it moves closer to being the first in the world to commercialize fusion power.

The oversubscribed round of capital is the largest amount raised among deep tech and energy companies since CFS’ $1.8 billion Series B round in 2021. CFS will use the funds to complete SPARC, its fusion demonstration machine, and progress on development work on its first ARC power plant in Virginia. To date, CFS has raised close to $3 billion, about one-third of the total capital invested in private fusion companies worldwide.

“Investors recognize that CFS is making fusion power a reality. They see that we are executing and delivering on our objectives,” said Bob Mumgaard, CEO and Co-founder. “This funding recognizes CFS’ leadership role in developing a new technology that promises to be a reliable source of clean, almost limitless energy — and will enable investors to have the opportunity to capitalize on the birth of a new global industry.”

In this round, CFS expanded its global footprint by adding international investors from a widening range of sectors — from long-established fundamental investors to industrial companies. In recognition of the new category of energy technology that the company is creating, CFS deepened and broadened its access across the financial ecosystem, with investors that span venture capitalists, private equity firms, sovereign wealth funds, leading individual investors, industrials, hedge funds, pension funds and banks.

New investors in CFS include (in alphabetical order): Brevan Howard Macro Venture Fund; Counterpoint Global (Morgan Stanley); Stanley Druckenmiller; FFA Private Bank (Dubai) Ltd.; Galaxy Interactive, a venture platform within Galaxy Digital Inc. (NASDAQ: GLXY); Gigascale Capital; HOF Capital; Neva SGR (Intesa Sanpaolo Bank); NVentures (NVIDIA’s venture capital arm); Planet First Partners; Woori Venture Partners US; and others committed to the mission of commercializing fusion energy.

A consortium of 12 Japanese companies led by Mitsui & Co., Ltd. and Mitsubishi Corporation also participated. The Japanese consortium included Development Bank of Japan Inc.; Fujikura Ltd.; JERA Co., Inc.; JGC Japan Corporation; Mitsui Fudosan Co., Ltd.; Mitsui O.S.K. Lines Ltd.; NTT, Inc.; Sumitomo Mitsui Banking Corporation; Sumitomo Mitsui Trust Bank Ltd.; and The Kansai Electric Power Co., Inc.

They join existing CFS investors who increased their stakes, including Breakthrough Energy Ventures; Emerson Collective; Eni; Future Ventures; Gates Frontier; Google; Hostplus Superannuation Fund; Khosla Ventures; Lowercarbon Capital; Safar Partners; Eric Schmidt, former CEO of Google; Starlight Ventures; Tiger Global;  a large state pension fund and others who support CFS’ leadership in this energy transition.

“CFS offers investors the clearest path to bringing commercial fusion to the world — and an unprecedented opportunity to make a real impact as global demand for power accelerates with electrification and increased use of AI and data centers,” said Ally Yost, Senior Vice President of Corporate Development at CFS. “Along with the promise of energy independence and security, fusion power will help to expand energy access, and with it, improve quality of life.”

The oversubscribed round validates that CFS is developing the most promising path to commercial fusion power in the coming years, as demonstrated by the company’s key advances in high-temperature superconducting magnets and its execution velocity in the construction of  SPARC in Devens, Massachusetts.

In parallel, CFS is moving forward with plans to build the world’s first grid-scale fusion power plant, called ARC, in Chesterfield County, Virginia. This effort to put power on the grid in the early 2030s is bolstered by strategic partnerships with Dominion Energy and Google — an investor in CFS that also agreed to buy half the power produced at the plant.

Perspectives from CFS investors:

“CFS is a rare fusion of visionary leadership, scientific breakthrough, and executional excellence – targeting one of the world’s biggest markets.  Counterpoint Global is excited to partner with CFS to help them achieve their mission to deliver affordable and abundant energy to power a sustainable future.” 
–Dennis Lynch, Head of Counterpoint Global (Morgan Stanley)

“At Khosla Ventures, we invest in bold and impactful projects, and CFS is one of the most impactful and ambitious projects I’ve seen in my career. Year after year, CFS has executed flawlessly.  Their ARC power plants will soon deliver limitless energy to fuel the age of AI driving a new wave of societal transformation.” —Vinod Khosla, Founder and Investor, Khosla Ventures

“Energy has always been the foundation of human progress, driving productivity, health, and prosperity. To meet the challenges of this century, we need energy that is abundant, clean, and accessible everywhere. That’s what fusion offers. For the first time in history, we have a real opportunity to commercialize the long-held promise of fusion power, and Commonwealth Fusion Systems has just taken a decisive step toward making that promise a reality.” –Laurene Powell Jobs, Founder and President, Emerson Collective

“CFS is pioneering one of the most credible and accelerated pathways to commercial fusion. Their breakthrough high-field magnet technology and pragmatic scaling strategy position them to deliver safe, reliable, and abundant clean energy, an outcome that could fundamentally reshape the global energy system.” —Hisham Elhaddad, Managing Partner at HOF Capital

“Achieving commercial, affordable fusion power would be one of the most transformative milestones in human history—delivering clean, limitless energy to help strengthen energy security and improve global living standards. CFS is advancing fusion at a pace and scale that can turn this future into reality—providing a unique opportunity to shape the energy landscape, especially as AI and data centers are driving unprecedented demand.” —Carmichael Roberts, Managing Partner, Breakthrough Energy Ventures

“We are excited to back Commonwealth Fusion Systems as they aim to transform decades of innovation in deep technologies into scalable, limitless power driving our future infrastructure. Their work exemplifies the kind of bold, world-changing ambition we are committed to supporting, and we are thrilled to partner in shaping the next era of global infrastructure.” —Sam Englebardt, General Partner of Galaxy Interactive, a venture platform within Galaxy Digital Inc. (NASDAQ: GLXY)

“Few technologies in our investable universe have the potential to reshape the global energy system – and therefore the climate trajectory – as profoundly as fusion power. CFS has assembled a world-class team which is executing on a highly credible plan to deliver net energy gain with SPARC, a transformational milestone. Planet First Partners is beyond excited to join Bob and the CFS team on their mission to make commercial fusion power a reality.” —Frédéric de Mévius, Executive Chairman and Managing Partner at Planet First Partners

“Every discovery that changes the world begins with those who have the courage to believe in it. CFS is working on the most advanced technology in the world, in a sector that will revolutionize our lives. As part of Italy’s leading bank, our investment in the company stems from the conviction that our country must play an active role in this transformation and involve its SMEs and manufacturing network in building a new industrial supply chain for clean and sustainable energy. We are committed to ensuring that this initiative has a systemic impact: the goal is to anticipate global trends, support the transformation of businesses, and generate skilled employment.” —Mario Costantini, CEO and General Manager Neva SGR (Intesa Sanpaolo Bank) 

“Eni has further strengthened its financial commitment to CFS, confirming our long-term involvement in the development of fusion energy. We consider this technology a game-changing breakthrough for achieving the energy transition goals. As a relative majority shareholder, Eni’s support for CFS extends beyond financial capital. We continue to provide critical operational, technological, and project execution support by sharing methodologies applied in the energy industry.” —Clara Andreoletti, CEO Eni Next

As one of Commonwealth Fusion Systems’ earliest investors, we’ve had a front-row seat to witness their exceptional execution and the remarkable growth of what we believe is one of the most talented teams in the deep tech space. Their consistent ability to hit aggressive milestones while building breakthrough technology has reinforced our conviction that CFS is positioned to lead the clean energy revolution. We are confident in the senior management team’s excellence, and their commitment to creating a better world for humanity. We’re proud to continue supporting a company that combines world-class innovation with the operational discipline needed to bring fusion power to market as soon as possible.” —Nader Motamedy, Managing Partner, Safar Partners

“Backing Commonwealth isn’t about chasing hype, it’s about supporting a team that is steadily advancing physics and engineering toward the most consequential breakthrough of our lifetime. This fundraise is one more step on that audacious path.” —Maryanna Saenko, Co-founder, Future Ventures

“CFS is redefining what it takes to build a deep tech unicorn. With one of the most scientifically vetted approaches to fusion and a team built to execute, they’re turning breakthrough science into a global industry.”—Mike Schroepfer, Founder, Gigascale Capital

“At FFA Private Bank Dubai, we are committed to backing transformative technologies with the potential to redefine entire industries. Commonwealth Fusion Systems represents exactly that — a bold leap toward limitless, clean energy. We are proud to support CFS in accelerating the transition from ambition to reality, shaping the future of global energy security and sustainability.” —Nadim Haidar, CEO of FFA Private Bank (Dubai) Ltd.

“We’ve been proud to support Commonwealth Fusion Systems since 2019 and every round since. Perhaps no other technology better reflects our mission of backing unstoppable teams solving humanity’s most critical challenges – and it’s humbling to see them bring abundant, carbon-free fusion energy closer to reality with disciplined execution.” —Matias Mosse, Founder of Starlight Ventures

About Commonwealth Fusion Systems
Commonwealth Fusion Systems is the world’s largest and leading private fusion company. The company’s marquee fusion project, SPARC, will generate net energy, paving the way for limitless carbon-free energy. The company has raised more than $3 billion in capital since it was founded in 2018.

Media contacts:
Commonwealth Fusion Systems
[email protected]

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