Every Fusion Startup That Has Raised Over $100M

Fusion power, once a distant dream, is rapidly becoming a tangible reality, drawing significant investor interest. Startups are harnessing the nuclear reaction that powers the sun, promising nearly limitless energy. Successfully building commercially viable fusion power plants could revolutionize trillion-dollar markets.

Advances in computer chips, AI, and high-temperature superconducting magnets are driving this bullish wave. These technologies enable more sophisticated reactor designs, better simulations, and complex control schemes. A U.S. Department of Energy lab achieved scientific breakeven in late 2022, producing more power from a controlled fusion reaction than the lasers used to initiate it, validating the underlying science.

Several startups have capitalized on this momentum, attracting substantial funding:

Commonwealth Fusion Systems

Commonwealth Fusion Systems (CFS) leads with a $1.8 billion Series B in 2021. They are constructing Sparc, a power plant in Massachusetts designed to produce commercially relevant power levels. Sparc utilizes a tokamak design with high-temperature superconducting tape to generate a powerful magnetic field, containing and compressing superheated plasma. In collaboration with MIT, CFS aims to have its commercial-scale Arc reactor operational in the early 2030s. Total funding: $2 billion.

TAE Technologies

Founded in 1998, TAE Technologies employs a field-reversed configuration, bombarding plasma with particle beams to maintain stability. This improves fusion time and heat extraction. In June 2025, they raised $150 million from investors like Google and Chevron, bringing their total to $1.79 billion.

Helion

Helion aims to produce electricity from its reactor by 2028, with Microsoft as its first customer. They use a field-reversed configuration, spinning plasma into doughnut shapes and colliding them at high speeds. Fusion boosts the plasma’s magnetic field, inducing an electrical current that is directly harvested. Helion raised $425 million in January 2025 and has secured $1.03 billion in total funding. Investors include Sam Altman, Reid Hoffman, and Peter Thiel’s Mithril Capital Management.

Pacific Fusion

Pacific Fusion entered the scene with a $900 million Series A, employing inertial confinement with coordinated electromagnetic pulses. CEO Eric Lander, who led the Human Genome Project, and president Will Regan lead the company. Funding is milestone-based, common in biotech.

Shine Technologies

Shine Technologies focuses on neutron testing and medical isotopes while developing capabilities for future fusion reactors. They are also exploring radioactive waste recycling. Shine has raised $778 million with investors including Energy Ventures Group and Koch Disruptive Technologies.

General Fusion

General Fusion, founded in 2002, employs magnetized target fusion (MTF). A liquid metal wall surrounds a chamber where plasma is injected and compressed. Neutrons heat the liquid metal to generate steam for a turbine. They faced financial challenges in spring 2025, laying off 25% of staff. Total funding: $440.53 million. Investors include Jeff Bezos and Temasek.

Tokamak Energy

Tokamak Energy utilizes a compact tokamak design with high-temperature superconducting magnets. Their ST40 prototype generated a 100 million degree C plasma in 2022. The next-generation Demo 4 will test magnets in fusion power plant conditions. They raised $125 million in November 2024, bringing their total to $336 million.

Zap Energy

Zap Energy uses an electric current to confine plasma, generating its own magnetic field. The fusion reaction heats a liquid metal blanket, producing steam for a turbine. They have raised $327 million with support from Bill Gates’ Breakthrough Energy Ventures and Chevron Technology Ventures.

Proxima Fusion

Proxima Fusion is pursuing stellarator designs, which stabilize plasma for longer durations. They attracted a €130 million Series A, bringing total funding to over €185 million. Investors include Balderton Capital and Cherry Ventures.

Marvel Fusion

Marvel Fusion employs inertial confinement, firing lasers at a target embedded with silicon nanostructures. They are building a demonstration facility with Colorado State University, expected to be operational by 2027. Total funding: $161 million.

First Light

First Light pivoted from fusion power to becoming a technology supplier. They had previously pursued inertial confinement. Total funding: $140 million.

Xcimer

Xcimer is redesigning the technology behind the National Ignition Facility’s net-positive experiment. They are developing a 10-megajoule laser system with molten salt walls. Total funding: $109 million.

The fusion industry is rapidly evolving, with significant investments and technological advancements driving progress towards commercial viability. This story will be continually updated to reflect the latest developments.