Over the last several years, fusion power has gone from the butt of jokes — always a decade away! — to an increasingly tangible and tantalizing technology that has drawn investors off the sidelines. The technology may be challenging to master and expensive to build today, but fusion promises to harness the nuclear reaction that powers the sun to generate nearly limitless energy here on Earth. If startups are able to complete commercially viable fusion power plants, then they have the potential to upend trillion-dollar markets. The bullish wave buoying the fusion industry has been driven by three advances: more powerful computer chips, more sophisticated AI, and powerful high-temperature superconducting magnets. Together, they have helped deliver more sophisticated reactor designs, better simulations, and more complex control schemes. It doesn’t hurt that, at the end of 2022, a U.S. Department of Energy lab announced that it had produced a controlled fusion reaction that produced more power than the lasers had imparted to the fuel pellet. The experiment had crossed what’s known as scientific breakeven, and while it’s still a long ways from commercial breakeven, where the reaction produces more than the entire facility consumes, it was a long-awaited step that proved the underlying science was sound. Founders have built on that momentum in recent years, pushing the private fusion industry forward at a rapid pace. Commonwealth Fusion Systems Commonwealth Fusion Systems (CFS) has raised about a third of all private capital invested in fusion companies to date. Its latest round, which closed in August, added $863 million to its coffers, bringing its total raised near $3 billion. CFS’s Series B2 came four years after its <head>.8 billion Series B, which helped catapult the company into the pole position. Since then, the startup has been hard at work in Massachusetts building Sparc, its first-of-a-kind power plant intended to produce power at what it calls “commercially relevant” levels. Techcrunch event San Francisco | October 13-15, 2026 Sparc’s reactor is a tokamak design, which resembles a doughnut. The D-shaped cross section is wound with high-temperature superconducting tape, which, when energized, generates a powerful magnetic field that will contain and compress the superheated plasma. Heat generated from the reaction is converted to steam to power a turbine. CFS designed its magnets in collaboration with MIT, where co-founder and CEO Bob Mumgaard worked as a researcher on fusion reactor designs and high-temperature superconductors. The Massachusetts-based CFS expects to have Sparc operational in late 2026 or early 2027. Later this decade, the company says it will begin construction on Arc, its commercial power plant that will produce 400 megawatts of electricity. The facility will be built near Richmond, Virginia, and Google has agreed to buy half its output. CFS is backed by a long list of investors, including Breakthrough Energy Ventures, The Engine, Bill Gates, and others. TAE Technologies Founded in 1998, TAE Technologies (formerly known as Tri Alpha Energy) was spun out of the University of California, Irvine by Norman Rostoker. It uses a field-reversed configuration, but with a twist: after the two plasma shots collide in the middle of the reactor, the company bombards the plasma with particle beams to keep it spinning in a cigar shape. That improves the stability of the plasma, allowing more time for fusion to occur and for more heat to be extracted to spin a turbine. In December 2025, TAE announced that it would merge with President Donald Trump’s social media company, Trump Media & Technology Group. The all-stock transaction would value the combined company at $6 billion. TAE would receive $200 million plus another <head>00 million upon filing paperwork with the Securities and Exchange Commission. TAE CEO Michl Binderbauer will serve as co-CEO of the combined company alongside Devin Nunes, who had been sole CEO of Trump Media. The fusion startup had previously raised <head>50 million in June from existing investors, including Google, Chevron, and New Enterprise. Before the merger, TAE had raised a total of <head>.79 billion, according to PitchBook. Helion Of all fusion startups, Helion has the most aggressive timeline. The company plans to produce electricity from its reactor in 2028. Its first customer? Microsoft. Helion, based in Everett, Washington, uses a type of reactor called a field-reversed configuration, where magnets surround a reaction chamber that looks like an hourglass with a bulge at the point where the two sides come together. At each end of the hourglass, they spin the plasma into doughnut shapes that are shot toward each other at more than 1 million mph. When they collide in the middle, additional magnets help induce fusion. When fusion occurs, it boosts the plasma’s own magnetic field, whic