In recent years, fusion energy has transitioned from being a punchline to a promising technological development that is attracting serious investment.
Though mastering fusion technology is currently complex and costly, it holds the potential to replicate the sun’s nuclear reactions, offering a nearly infinite energy source for Earth. Successful commercial fusion plants could disrupt trillion-dollar energy markets.
The surge in interest within the fusion sector has been fueled by three key advancements: enhanced computer chips, advanced artificial intelligence, and high-temperature superconducting magnets. These innovations have allowed for more advanced reactor designs, improved simulations, and intricate control systems.
In December 2022, a U.S. Department of Energy laboratory reported achieving a controlled fusion reaction that generated more energy than was provided by the lasers to the fuel pellet, marking a significant scientific milestone. Although commercial viability is still far off, this breakthrough confirmed the fundamental science behind fusion.
This momentum has driven numerous entrepreneurs to propel the private fusion sector forward.
Commonwealth Fusion Systems
Commonwealth Fusion Systems (CFS) has secured roughly one-third of private investment in fusion enterprises, recently closing an $863 million funding round that brings its total funding to nearly $3 billion. The company’s Series B2 funding was bolstered by a previous $1.8 billion Series B round four years earlier, positioning CFS at the forefront of the industry.
CFS is currently constructing Sparc, a unique power plant designed to produce what it terms “commercially relevant” energy levels. The Sparc reactor employs a tokamak design, with a D-shaped profile wrapped in high-temperature superconducting tape that generates a strong magnetic field to contain and compress the plasma. Heat from the fusion reaction will be converted into steam to power a turbine. The CFS team collaborated with MIT, where co-founder and CEO Bob Mumgaard has a background in fusion reactor engineering.
CFS aims to have Sparc operational by late 2026 or early 2027 and anticipates beginning construction on Arc, a commercial facility generating 400 megawatts near Richmond, Virginia, later this decade. Notably, Google has signed on to purchase half of Arc’s electricity output.
CFS is funded by various notable investors, including Breakthrough Energy Ventures and Bill Gates.
TAE Technologies
Established in 1998, TAE Technologies originated from the University of California, Irvine, founded by Norman Rostoker. It employs a field-reversed configuration technique, enhancing the plasma stability by bombarding it with particle beams after initial fusion events, which lengthens the duration for effective fusion reactions.
In December 2025, TAE announced a merger with Trump Media & Technology Group, valuing the joint entity at $6 billion. TAE will receive $200 million upfront, plus an additional $100 million upon SEC filing. Michl Binderbauer, TAE’s CEO, will co-lead the new company alongside Devin Nunes, the former sole Trump Media chief.
Earlier in June, TAE secured $150 million from existing investors like Google and Chevron, bringing its total funding to $1.79 billion, according to PitchBook.
Helion
Helion boasts one of the most ambitious timelines among fusion startups, aiming to produce its first electricity by 2028, with Microsoft as its prospective client.
Operating from Everett, Washington, Helion employs a field-reversed configuration reactor featuring an hourglass-shaped reaction chamber. Plasma is spun into doughnut shapes and directed towards one another at high velocities, with additional magnets enhancing the fusion process. The resulting fusion event boosts the plasma’s magnetic field, generating electricity directly from the coils.
In June, Helion raised $465 million in a Series G funding round that valued the company at $15.5 billion, following $425 million raised in January 2025. Overall, Helion claims to have amassed $1.5 billion, with investors including Sam Altman and KKR.
Pacific Fusion
Pacific Fusion rapidly raised over $1 billion in its Series A funding round, a remarkable feat among fusion startups. The company intends to use inertial confinement for fusion, employing synchronized electromagnetic pulses rather than lasers to compress fuel. The timing for this process is critical, as all 156 generators must achieve 2 terawatts for 100 nanoseconds simultaneously.
Led by CEO Eric Lander, known for his role in the Human Genome Project, Pacific Fusion’s funding involves milestone-based payouts, common in biotech investments.
Shine Technologies
Shine Technologies is opting for a cautious approach to fusion energy. While full-scale power generation remains distant, the company is currently focusing on selling neutron testing and medical isotopes, and developing recycling processes for radioactive waste. Shine is keeping its options open regarding future reactor designs as it builds necessary expertise.
To date, Shine has raised $1 billion, with major investors including Energy Ventures Group and Koch Disruptive Technologies, and a recent $240 million round led by NantWorks.
General Fusion
Founded in 2002 by physicist Michel Laberge, General Fusion has raised over $600 million and is based in Richmond, British Columbia. The company experiments with magnetized target fusion (MTF) and employs a liquid metal wall to surround its plasma chamber, using pistons to compress the plasma for fusion.
In 2025, General Fusion faced financial difficulties while constructing its latest reactor, LM26. Despite laying off a quarter of its staff, they managed to secure funding from investors, including a $51.1 million round from various sources. Their total funding now sits at $612 million.
The company plans to go public through a reverse merger with a special-purpose acquisition vehicle, potentially raising an additional $335 million.
Inertia Enterprises
Inertia Enterprises was founded by key players from the National Ignition Facility (NIF) and aims to commercialize similar technology using lasers to compress fuel pellets. They recently initiated funding with $450 million in Series A financing, led by Bessemer Venture Partners.
Focused Energy
Headquartered in Germany, Focused Energy is also using laser pulses for fuel compression. The company has hired former NIF personnel to mass-produce custom fuel targets. Having attracted $240 million in a Series A funding round, their total funding now exceeds $400 million, supported by grants from significant entities.
Tokamak Energy
Tokamak Energy modifies the traditional tokamak design, creating a more compact version that cuts costs while utilizing high-temperature superconducting magnets. Their prototype, ST40, achieved plasma temperatures of 100 million degrees Celsius, and they’ve launched continued expansion into magnet business partnerships.
The firm raised $125 million recently, totaling $336 million in funding, engaged in projects like the UK’s STEP Fusion program.
Zap Energy
Instead of traditional confinement methods, Zap Energy relies on electric currents to maintain plasma. Recently, they pivoted towards a hybrid approach combining fusion and fission, anticipating earlier revenue generation. Their total fundraising stands at $327 million, with investments from notable backers.
Type One Energy
Type One aims to construct a fusion reactor on a former coal plant site, projecting 350 megawatts of output by the mid-2030s. Instead of operating their own facility, they plan to supply technology to organizations, raising $269 million so far.
Proxima Fusion
Breaking away from the trend, Proxima Fusion has successfully raised €130 million in Series A funding, focusing on stellarators—offering potential stability advantages for plasma handling over traditional methods.
Kyoto Fusioneering
Kyoto Fusioneering is addressing the need for auxiliary components in fusion power plants. This balance of plant includes various systems to extract and manage energy output from fusion reactions. The startup has raised $191 million from various investors, betting on the industry’s future success.
Marvel Fusion
Marvel Fusion utilizes inertial confinement through laser technology to initiate fusion reactions. Their innovative approach involves creating silicon targets for easier manufacture and plans to complete a demonstration facility by 2027, having raised $162 million thus far.
Thea Energy
Thea Energy is exploring a novel method for constructing a stellarator using pixel-inspired magnets to create complex magnetic fields efficiently. The company has raised $130 million from various investors, pursuing an innovative path in fusion technology.
First Light Fusion
First Light Fusion follows an atypical route by employing a projectile launcher for inertial confinement rather than lasers. The UK-based startup plans to license its technology to others for power plant construction, having raised $108 million in funding.
Xcimer
Xcimer aims to push the boundaries of fusion technology with its ambitious 10-megajoule laser system. Located in Colorado, the startup recently activated a prototype that asserts to be the world’s most powerful private laser, raising $100 million from a range of investors.
This article was initially published in September 2024 and will be updated periodically.
