Over the past several years, fusion energy has transitioned from a long-shot scientific dream to a serious commercial pursuit, attracting over $100 million in funding from a growing number of startups. Driven by advances in high-temperature superconducting magnets, powerful computing, and AI-driven simulations, these companies are racing to make fusion a viable, scalable energy source. The landmark 2022 achievement at the U.S. Department of Energy’s National Ignition Facility—where a fusion reaction produced more energy than the lasers that triggered it—marked a turning point, proving the science was possible and spurring private investment. Here is a list of fusion startups that have raised over $100 million, each pursuing a different path to commercial fusion: Commonwealth Fusion Systems (CFS) has raised nearly $3 billion, the most of any private fusion company. Backed by Bill Gates, Breakthrough Energy Ventures, and The Engine, CFS is building Sparc, a compact tokamak reactor in Massachusetts, with a target for operation by late 2026 or early 2027. The company plans to follow with Arc, a 400-megawatt commercial plant in Virginia, with Google committed to purchasing half its output. TAE Technologies, founded in 1998, has raised $1.79 billion and uses a field-reversed configuration reactor. In December 2025, it announced a merger with Trump Media & Technology Group, creating a combined entity valued at $6 billion. TAE will receive $200 million upfront and an additional $100 million upon SEC filing, with CEO Michl Binderbauer becoming co-CEO. Helion Energy, based in Washington state, aims to deliver electricity by 2028, with Microsoft as its first customer. It uses a field-reversed configuration reactor that directly converts fusion energy into electricity. Helion has raised $1.03 billion, including a $425 million round in January 2025, with investors like Sam Altman, Peter Thiel, BlackRock, and KKR. Pacific Fusion raised $900 million in a single Series A, one of the largest in fusion history. It uses electromagnetic pulses instead of lasers for inertial confinement, with 156 synchronized generators firing in perfect timing. Led by Eric Lander, former head of the Human Genome Project, the company’s funding is milestone-based, a model common in biotech. Shine Technologies takes a pragmatic approach, focusing on selling neutron sources for medical isotope production and radioactive waste recycling. It has raised $778 million and is developing fusion readiness without committing to a full power plant yet. General Fusion, founded in 2002, has raised $492 million using magnetized target fusion. Its reactor compresses plasma with pistons pushing liquid metal walls. After a funding shortfall in 2025 led to layoffs and a $22 million pay-to-play round, it secured an additional $51.1 million in SAFE notes to stay operational. Tokamak Energy, based in Oxfordshire, UK, raised $336 million using compact tokamak designs with high-temperature superconducting magnets. Its ST40 reactor achieved 100 million degree plasma in 2022. The company is building Demo 4 to test fusion-relevant conditions. Zap Energy, also in Washington, uses a z-pinch method where electric current generates self-confining magnetic fields. It has raised $327 million from investors including Bill Gates and Chevron Technology Ventures. Proxima Fusion, a stellarator-focused startup, raised €130 million in a Series A, bringing its total to over €185 million. Stellarators use twisted magnetic fields to stabilize plasma longer than traditional tokamaks. Investors include Balderton Capital and Cherry Ventures. Kyoto Fusioneering has raised $191 million to develop balance-of-plant components—gyrotrons, heat exchangers, and power conversion systems—critical for future fusion plants. Backed by Mitsubishi, Sumitomo Mitsui Trust, and In-Q-Tel, it positions itself as a supplier for the broader fusion ecosystem. Marvel Fusion, based in Munich, uses inertial confinement with laser-driven silicon nanostructured targets. It’s building a demonstration facility with Colorado State University, aiming for operation by 2027. It has raised $162 million from investors including Deutsche Telekom and HV Capital. First Light Fusion, based in Oxford, UK, uses a projectile-based inertial confinement system, firing a piston to compress fusion fuel. In 2025, it shifted strategy, abandoning plans for its own power plant and instead focusing on licensing its technology and building a pulsed power demonstrator with defense and scientific applications. It has raised $108 million. Xcimer, founded in 2022 in Colorado, is developing a 10-megajoule laser system—five times more powerful than NIF’s—using molten salt walls to absorb heat. It has raised $100 million from Breakthrough Energy Ventures, Emerson Collective, and Lowercarbon Capital. These companies represent a diverse and rapidly evolving fusion landscape, united by the ambition to deliver clean, abundant energy from the power of the sun.