For years, fusion power was the punchline of energy jokes - perpetually a decade away, like that friend who's always 'about to start a diet.' But recent advances in computer chips, AI, and high-temperature superconducting magnets have turned the technology into something investors actually want to fund. The U.S. Department of Energy's 2022 achievement of scientific breakeven didn't hurt either, proving that the underlying science works, even if commercial breakeven remains a distant fantasy.
Commonwealth Fusion Systems (CFS) leads the pack with nearly $3 billion raised, including $863 million from its latest round in August. The Massachusetts-based startup is building Sparc, a tokamak reactor that looks like a doughnut with a magnetic field strong enough to contain superheated plasma. CFS expects Sparc to be operational by late 2026 or early 2027, followed by its commercial plant Arc, which will produce 400 megawatts of electricity near Richmond, Virginia. Google has already agreed to buy half of that output, presumably to power its AI servers that are busy generating cat pictures.
TAE Technologies, founded in 1998, has raised $1.79 billion and recently announced a merger with Trump Media & Technology Group in an all-stock deal valuing the combined company at $6 billion. Because nothing says 'fusion energy' like a social media platform. TAE will receive $200 million upfront, with another $100 million upon SEC filing. CEO Michl Binderbauer will co-lead with Devin Nunes, who previously ran Trump Media.
Helion has the most aggressive timeline, planning to produce electricity for Microsoft by 2028. The Everett, Washington-based startup uses a field-reversed configuration where plasma doughnuts collide at over 1 million mph. It has raised $1.5 billion from investors including Sam Altman, SoftBank, and Peter Thiel's Mithril Capital.
Pacific Fusion burst out with a $1 billion Series A - yes, billion with a B - using inertial confinement with electromagnetic pulses instead of lasers. The trick involves synchronizing 156 generators to produce 2 terawatts for 100 nanoseconds. CEO Eric Lander, who led the Human Genome Project, is apparently now in the business of splitting atoms instead of sequencing them.
Shine Technologies takes a pragmatic approach, selling neutron testing and medical isotopes while developing radioactive waste recycling. It has raised $1 billion from investors including Koch Disruptive Technologies and hasn't even picked a reactor design yet.
General Fusion, now in its third decade, has raised $612 million from investors including Jeff Bezos. The company hit a rough patch in spring 2025, laying off 25% of staff after running short of cash. It received $22 million in a 'pay-to-play' round that one investor called 'the least amount of capital possible' to keep the company alive. In January, General Fusion announced plans to go public via a SPAC merger.
Inertia Enterprises emerged from stealth in February with $450 million in Series A funding. The company's chief scientist, Annie Kircher, helped achieve the only scientific breakeven at the National Ignition Facility. The founding team includes Twilio co-founder Jeff Lawson, who currently owns The Onion - fitting, given fusion's history as a joke.
Focused Energy, another NIF spinoff, raised $240 million in an oversubscribed Series A. The company aims to mass-produce fuel targets at nearly 1 million per day, which sounds ambitious until you remember that's roughly how many excuses fusion skeptics make annually.
Tokamak Energy squishes the traditional doughnut design into a sphere, requiring fewer magnets and lower costs. The Oxfordshire-based startup raised $125 million in November 2024 and is supplying magnets for the U.K.'s STEP Fusion program. Its ST40 prototype generated a 100-million degree Celsius plasma in 2022, which is hot enough to make even the most skeptical investor sweat.
Zap Energy uses electric current to generate its own magnetic field, compressing plasma to about 1 millimeter until ignition occurs. Because sometimes the simplest solution - zapping things - is the best one.