# All Fusion Startups with $100M+ Funding
The fusion energy sector is experiencing unprecedented investment fervor, with private startups collectively raising billions toward commercializing clean, limitless power. As of late 2025, at least 13 fusion companies have secured over $100 million each in funding, led by giants like Commonwealth Fusion Systems with nearly $3 billion, signaling a pivotal race to harness the sun's power on Earth.[2][6]
Leading Fusion Startups and Their Massive Funding Hauls
Commonwealth Fusion Systems (CFS) tops the list with approximately $3 billion raised, including an $863 million Series B2 round in August 2025 backed by investors like Nvidia’s NVentures. The Massachusetts-based pioneer is advancing its SPARC tokamak reactor, aiming for operational status by late 2026, with Google committed to buying power from its first commercial plant.[2][3][6][7] TAE Technologies, founded in 1998, follows with $1.79 billion, employing field-reversed configuration plasma stabilized by particle beams; recent rounds included Google's participation.[6][8] Helion Energy has amassed over $778 million (with a $425 million Series F in early 2025), activating its Polaris prototype reactor around the same time.[2][5][7]
Other heavyweights include Pacific Fusion, which emerged from stealth with a record $900 million Series A for electromagnetic pulse-driven inertial confinement fusion.[2][5] General Fusion totals $492 million, bolstered by recent $22 million and $51.1 million raises to sustain operations.[2]
Emerging Players Breaking the $100M Barrier
Beyond the frontrunners, innovative startups are rapidly scaling. Xcimer Energy, launched in 2022, hit $100 million from backers like Breakthrough Energy Ventures for laser-based fusion.[1][2] Germany's Proxima Fusion raised €130 million (~$148 million) in Series A for stellarator tech, while Tokamak Energy secured $125 million for compact spherical tokamaks.[1] Marvel Fusion grabbed €113 million in Series B, contributing to Europe's fusion surge.[5]
Government programs amplify private funds: The U.S. DOE's Milestone-Based Fusion Development Program supports CFS and others with up to $415 million, while the UK's £410 million (~$476 million) initiative backs fusion research.[4] The sector raised $2.64 billion in the year to July 2025 alone, pushing total funding for 53 companies to $9.766 billion.[5]
Technological Approaches Powering the Fusion Boom
These startups employ diverse paths to fusion. CFS and Tokamak Energy use tokamaks with high-temperature superconductors for magnetic confinement.[1][2][6] Pacific Fusion and Xcimer pursue inertial confinement via electromagnetic pulses or lasers, timing pulses precisely for 2-terawatt bursts.[1][2] Helion's pulsed magnetic approach powers its prototypes, while TAE's particle beam stabilization marks a unique field-reversed design.[2][6]
Breakthroughs like the 2022 U.S. National Ignition Facility's scientific breakeven have fueled optimism, with 84% of companies eyeing grid electricity by 2030s' end.[5][6] Investors span VCs like DCVC, corporates like Chevron and Siemens Energy, and funds including In-Q-Tel.[5]
Investment Trends and Path to Commercialization
Fusion funding hit record levels in 2025, with CFS's $863 million and Helion's $425 million underscoring momentum.[3][5][7] Total private investment reached $7.1 billion across these 13 leaders, a five-fold rise since 2021.[5][6] Notable deals include Pacific Fusion's stealth exit and TAE's potential $6 billion merger with Trump Media, injecting up to $300 million cash.[8]
Challenges persist, but confidence abounds: 53% of firms target 2035 for grid fusion.[5] This influx positions fusion as a viable clean energy contender amid global decarbonization pushes.
Frequently Asked Questions
What is the total funding raised by fusion startups with over $100M?
Thirteen startups have raised over **$7.1 billion** collectively, with the sector totaling **$9.766 billion** across 53 companies as of mid-2025.[5][6]
Which fusion startup has raised the most funding?
**Commonwealth Fusion Systems** leads with nearly **$3 billion**, including an $863 million Series B2 in August 2025.[2][3][6]
What technologies do these high-funded fusion startups use?
Approaches include tokamaks (CFS, Tokamak Energy), inertial confinement (Pacific Fusion, Xcimer), field-reversed configurations (TAE), and pulsed magnetic systems (Helion).[1][2][6]
How much did the fusion industry raise in 2025?
Fusion companies secured **$2.64 billion** in the 12 months to July 2025, the second-highest yearly total.[5]
When do fusion startups expect to deliver grid power?
84% anticipate electricity to the grid before 2040, with 53% targeting by 2035.[5]
Who are the top investors in $100M+ fusion startups?
Key backers include Breakthrough Energy Ventures, Google, Nvidia, Chevron, Siemens Energy, and SoftBank.[2][3][5][6][7]
🔄 Updated: 12/31/2025, 3:20:14 PM
**LIVE FUSION FUNDING UPDATE:** Commonwealth Fusion Systems leads with nearly **$3 billion** raised, including an **$863 million Series B2** in August 2025 from Nvidia’s NVentures, powering its SPARC tokamak reactor targeting net energy by late 2026 and quoting CEO Bob Mumgaard: "We're not just building a power plant — we're building the future of energy."[6][7] Helion Energy follows at **$1.03 billion** total after a **$425 million Series F** in January 2025, demoing its Polaris prototype for direct electricity harvest via field-reversed configuration to supply Microsoft by 2028, while Pacific Fusion's **$900 million Serie
🔄 Updated: 12/31/2025, 3:30:22 PM
**LONDON** – The UK government announced a £20 million investment into Starmaker One, the world's first government-backed private fusion venture capital fund, expected to unlock over £100 million total for startups like Tokamak Energy and First Light Fusion, both with $100M+ funding.[1] This pioneering partnership aims to train workforces in physics, engineering, and chemistry while positioning Britain as a "clean energy superpower," building on a prior £410 million commitment for fusion research.[1] No similar direct government funding responses reported for other $100M+ fusion leaders like Commonwealth Fusion Systems or Helion Energy as of today.[2][3][5][6]
🔄 Updated: 12/31/2025, 3:40:19 PM
**Fusion Energy Funding Update:** Commonwealth Fusion Systems solidified its lead with an $863 million Series B2 round in August 2025, pushing its total funding to nearly $3 billion—about a third of all private fusion capital—and advancing its SPARC power plant toward commercially relevant output[2][3]. Helion Energy followed with $425 million in Series F funding in July 2025, led by Sam Altman and SoftBank, boosting its valuation past $5 billion after activating its Polaris prototype[2][3]. Pacific Fusion's explosive $900 million Series A for electromagnetic pulse-driven inertial confinement further intensified competition among the $100M+ club, including Tokamak Energy ($125M) and Xcimer Energy ($10
🔄 Updated: 12/31/2025, 3:50:18 PM
**Fusion Funding Surge Update:** Commonwealth Fusion Systems, the top-funded fusion startup with nearly **$3 billion** raised including an **$863 million Series B2** in August 2025 from investors like Nvidia’s NVentures, is advancing its SPARC reactor toward commercialization by late 2026[5][6][7]. Pacific Fusion announced a **$1 billion** investment in a New Mexico research campus in September 2025 to demo net-positive energy by 2030 using electromagnetic pulses from 156 Marx generators delivering **2 terawatts** for **100 nanoseconds**[2][8]. Helion Energy activated its Polaris prototype in January 2025 after a **$425 million** raise, targeting grid electricit
🔄 Updated: 12/31/2025, 4:00:20 PM
**Fusion Energy Stocks Surge on $7.1B Private Investment Milestone**: Shares of publicly traded backers like Chevron and Siemens Energy jumped 4-6% today amid reports that 13 fusion startups, including Commonwealth Fusion Systems ($3B raised) and Helion Energy ($1.03B total), have collectively secured over $7.1B in funding, fueling optimism for commercial breakthroughs by 2028[6][5]. Commonwealth Fusion's recent $863M Series B2 round, backed by Nvidia’s NVentures, drove a 2.5% spike in Nvidia stock as markets bet on fusion's trillion-pound global potential, with CFS CEO Bob Mumgaard declaring, "We're not just building a power plan
🔄 Updated: 12/31/2025, 4:10:29 PM
**Fusion Energy Stocks Surge on $2.64B Funding Wave**: Shares of publicly traded fusion backers like Chevron and Siemens Energy jumped 4-6% today amid news that fusion startups with $100M+ funding—led by Commonwealth Fusion Systems' nearly $3B total and Pacific Fusion's $900M Series A—drove $2.64B in sector investments over the past year.[4][6] Helion Energy's $425M raise coincided with activating its Polaris prototype, boosting investor sentiment and lifting related energy ETFs by 3.2%, as VCs eye 2030s grid commercialization.[3][5] "We're not just building a power plant—we're building the future of energy,
🔄 Updated: 12/31/2025, 4:20:26 PM
**Fusion Energy Funding Update:** Commonwealth Fusion Systems (CFS) solidified its dominance by raising $863 million in an August 2025 Series B2 round, pushing its total funding to nearly $3 billion—over a third of all private fusion capital—and securing a 500-MW power purchase agreement with Google for its ARC reactor in Virginia.[1][2][5] Helion Energy followed with $425 million in Series F funding in July 2025, led by Sam Altman and SoftBank, boosting its valuation above $5 billion amid activation of its Polaris prototype.[2][3] Pacific Fusion emerged as a fierce contender, clinching a record $900 million Series A for electromagnetic pulse-based inertial confinement fusion, inten
🔄 Updated: 12/31/2025, 4:30:28 PM
**Fusion Industry Association experts report 84% of surveyed fusion startups with $100M+ funding, including leaders like Commonwealth Fusion Systems ($3B total, $863M Series B2 in Aug 2025) and Pacific Fusion ($900M Series A), expect grid electricity by end-2030s, with 53% targeting 2035.** Commonwealth co-founder Bob Mumgaard emphasized, "We're not just building a power plant — we're building the future of energy," amid $2.64B invested industry-wide in the year to July 2025[4][5]. Analysts note U.S. firms captured over $10B globally, with Helion Energy's CEO David Kirtley pushing a 202
🔄 Updated: 12/31/2025, 4:40:28 PM
The UK government has launched a **£20 million investment into "Starmaker One,"** a private fusion venture capital fund designed to unlock an additional £100 million from private sector investors—marking the first government partnership with an early-stage fusion venture capital fund outside the US[1]. This funding boost follows a record £410 million government commitment announced in January for UK fusion research and represents a strategic effort to position Britain as a world leader in fusion technology while creating skilled jobs in physics, engineering, and chemistry[1]. The government investment signals growing regulatory confidence in fusion's commercial viability, with the sector having attracted $7.1 billion in total private funding globally, concentrated among 13 companies racing to deliver grid-
🔄 Updated: 12/31/2025, 4:50:29 PM
**LONDON (Breaking News) —** The UK's government has ignited a global fusion race by injecting £20 million into Starmaker One, the world's first early-stage fusion venture capital fund outside the US, poised to unlock over £100 million total for startups like Tokamak Energy ($336M raised) and First Light Fusion ($108M), cementing Britain as a clean energy superpower amid a sector-wide $7.1 billion private investment surge across 13 firms with $100M+ funding.[1][3][4][7] International responses are accelerating, with Germany's Proxima Fusion securing €130M (~$148M) for stellarators, Japan's Kyoto Fusioneering raising $191M from Mitsubishi and Sumi
🔄 Updated: 12/31/2025, 5:00:43 PM
**Pacific Fusion secures record $900M Series A for electromagnetic inertial confinement approach**, with plans to invest an additional $1 billion in a New Mexico research and manufacturing campus expected to achieve net-positive energy by 2030[3][8]. Commonwealth Fusion Systems remains the sector leader with nearly $3 billion raised, including an $863 million Series B2 round in August 2025, with its SPARC demonstration reactor targeted for late 2026 operation[5][6]. Across the industry, 13 fusion startups have collectively raised over $7.1 billion, with more than 75 percent of companies surveyed by the Fusion Industry Association expecting to
🔄 Updated: 12/31/2025, 5:10:32 PM
**LIVE FUSION FUNDING UPDATE:** The UK government announced a £20 million investment into Starmaker One, the world's first government-backed private fusion venture capital fund outside the US, poised to unlock over £100 million total for startups in physics, engineering, and magnetics technologies[1]. Meanwhile, Pacific Fusion secured a massive $900 million Series A to deploy 156 Marx generators delivering 2 terawatts for inertial confinement fusion, while Commonwealth Fusion Systems nears $3 billion in total funding after Google committed to buying 50% of its planned 400-megawatt ARC plant's output[4][3]. Fusion startups globally have now raised $7.1 billion, with 13 firms exceeding $10
🔄 Updated: 12/31/2025, 5:20:30 PM
**Fusion Industry Experts Highlight Execution Risks Amid $7.1B Funding Surge for 13 Startups Over $100M**, led by Commonwealth Fusion Systems' nearly $3B haul including an $863M Series B2[2][5][6]. Fusion Industry Association data shows 84% of companies expect grid electricity before 2040, with 53% by 2035, but analysts stress the "next test is execution—delivering net energy at plant scale, at costs utilities can underwrite," fueled by AI controls and superconductors[2][4]. Commonwealth co-founder Bob Mumgaard declared, "We're not just building a power plant—we're building the future of energy," as Helion eyes Microsoft power b
🔄 Updated: 12/31/2025, 5:30:35 PM
**LONDON** — The UK government has launched a pioneering £20 million investment into Starmaker One, the world's first government-backed private fusion venture capital fund targeting startups like Tokamak Energy ($336M raised) and First Light Fusion ($108M raised), expected to unlock over £100 million total for the sector.[1] This initiative, part of a broader £410 million commitment to fusion R&D announced in January, aims to train workforces in physics and engineering while positioning Britain as a "clean energy superpower" through commercialization of technologies like compact tokamaks.[1] Officials hailed it as a "world first government partnership with fusion private venture capital," cementing the UK's lead in the global fusion race amid surging privat
🔄 Updated: 12/31/2025, 5:40:31 PM
**FUSION FUNDING UPDATE: Commonwealth Fusion Systems (CFS) solidified its lead in the $100M+ club by raising $863 million in its August 2025 Series B2 round, pushing total funding near $3 billion and outpacing rivals like Helion Energy's $1.03 billion after a $425 million Series F in July 2025.**[3][4] Helion's funding, led by Sam Altman and SoftBank, valued it over $5 billion amid Polaris prototype activation, while Pacific Fusion's $900 million Series A for pulsed inertial confinement intensified competition across 13+ firms spanning tokamaks, stellarators, and Z-pinches—exemplified by Pr