Over the last several years, fusion power has transitioned from a long-term aspiration to a rapidly developing technology attracting significant investment. While challenges remain, the potential to harness the nuclear reaction powering the sun for nearly limitless energy is driving innovation and attracting capital to startups aiming to upend the energy market. This emerging field promises a clean and sustainable energy source, but commercial viability is still years away.
The recent surge in interest and funding for fusion energy is fueled by advancements in computing power, artificial intelligence, and high-temperature superconducting magnets. These breakthroughs have enabled more sophisticated reactor designs, improved simulations, and more complex control systems. A key milestone was achieved in late 2022 when a U.S. Department of Energy lab demonstrated a controlled fusion reaction producing more energy than the lasers used to initiate it – a critical step known as scientific breakeven.
The Rise of Private Fusion Companies
Several private companies are leading the charge in developing commercially viable fusion power plants. These ventures are attracting substantial investment, with billions of dollars flowing into the sector. Each company is pursuing different approaches to achieving sustained fusion, ranging from tokamak designs to inertial confinement fusion.
Commonwealth Fusion Systems
Commonwealth Fusion Systems (CFS) has secured approximately one-third of all private capital invested in fusion companies, totaling nearly $3 billion as of August 2024. The company’s Series B2 funding round will support the construction of Sparc, a first-of-a-kind power plant designed to produce commercially relevant levels of energy. Sparc utilizes a tokamak design, employing powerful high-temperature superconducting magnets to contain and compress superheated plasma.
CFS anticipates Sparc will be operational in late 2026 or early 2027, paving the way for Arc, a planned 400-megawatt commercial power plant near Richmond, Virginia. Google has already committed to purchasing half of Arc’s electricity output. The company’s investors include Breakthrough Energy Ventures and Bill Gates.
TAE Technologies
Founded in 1998, TAE Technologies utilizes a field-reversed configuration reactor, employing particle beams to stabilize plasma and enhance fusion efficiency. The company has raised $1.79 billion to date, according to PitchBook. In a surprising turn of events, TAE announced in December 2025 a merger with Trump Media & Technology Group, valuing the combined company at $6 billion. Michl Binderbauer, TAE’s CEO, will serve as co-CEO alongside Devin Nunes.
Helion
Helion is pursuing an aggressive timeline, aiming to produce electricity from its reactor by 2028, with Microsoft as its first customer. The company’s reactor uses a field-reversed configuration, colliding plasma doughnuts at over 1 million mph to induce fusion. Helion has raised $1.03 billion, backed by investors including Sam Altman and KKR.
Pacific Fusion
Pacific Fusion launched with a substantial $900 million Series A funding round. The company is employing inertial confinement fusion, utilizing coordinated electromagnetic pulses instead of lasers to compress fuel. Its funding is structured with milestones, ensuring capital disbursement based on achieving specific goals. CEO Eric Lander, formerly of the Human Genome Project, leads the company.
Shine Technologies
Shine Technologies is taking a phased approach, initially focusing on neutron testing and medical isotope production before pursuing full-scale fusion energy generation. The company has raised $778 million and is also exploring radioactive waste recycling technologies. Investors include Energy Ventures Group and Koch Disruptive Technologies.
General Fusion
General Fusion, established in 2002, employs magnetized target fusion (MTF). The company faced financial challenges in 2025, leading to layoffs and a plea for additional funding. However, recent investment rounds totaling $492 million, including a $22 million injection in August and $51.1 million in SAFE notes in November, have kept the company afloat. Investors include Jeff Bezos and Temasek.
Tokamak Energy
Tokamak Energy is refining the traditional tokamak design by reducing its aspect ratio, aiming for a more compact and cost-effective reactor. The company achieved a 100 million degree Celsius plasma in 2022 and is currently constructing Demo 4, a prototype to test its magnets. Tokamak Energy has raised $336 million from investors including Future Planet Capital and In-Q-Tel.
Zap Energy
Zap Energy utilizes an innovative approach, employing an electric current to generate the magnetic field necessary for plasma confinement. The company has secured $327 million in funding from investors including Bill Gates’ Breakthrough Energy Ventures.
Proxima Fusion
Proxima Fusion is focusing on stellarator technology, a complex but potentially more stable alternative to tokamaks. The company recently raised €130 million in a Series A round, bringing its total funding to over €185 million. Investors include Balderton Capital and Cherry Ventures.
Kyoto Fusioneering
Kyoto Fusioneering is concentrating on developing the “balance of plant” components necessary for a functioning fusion reactor, recognizing the need for specialized equipment beyond the core fusion process. The company has raised $191 million from investors including 31Ventures and Mitsubishi.
Marvel Fusion
Marvel Fusion is adapting the inertial confinement fusion approach used at the National Ignition Facility, focusing on silicon nanostructures to enhance compression efficiency. The company has raised $100 million from investors including Hedosophia and Breakthrough Energy Ventures.
First Light Fusion
First Light Fusion is pursuing inertial confinement fusion using a unique projectile-based system. The company has shifted its strategy to focus on technology licensing rather than building its own power plant, raising $108 million from investors including Invesco and Tencent.
Xcimer
Xcimer is developing a high-power laser system for inertial confinement fusion, aiming for a 10-megajoule output. The company has raised $100 million from investors including Breakthrough Energy Ventures.
The fusion energy landscape remains dynamic and uncertain. While significant progress has been made, numerous technical and economic hurdles remain. The next few years will be critical as companies like CFS and Helion work towards demonstrating sustained, commercially viable fusion reactions. Key milestones to watch include the operation of Sparc, the success of Helion’s Polaris reactor, and the continued development of advanced materials and technologies. The timeline for widespread adoption of fusion power remains ambitious, but the potential rewards are immense.
