Fusion power, once a distant dream, has rapidly evolved into a tangible and tantalizing technology, attracting significant investor interest. To date, fusion startups have collectively raised an impressive $7.1 billion, with a substantial portion flowing into a select group of companies. This surge in investment underscores a renewed optimism that harnessing the sun's power on Earth could soon revolutionize trillion-dollar energy markets, delivering nearly limitless clean energy.

The journey to mastering fusion remains challenging and capital-intensive, yet its promise is immense. A bullish wave has propelled the fusion industry, driven by three key technological advancements: more powerful computer chips, sophisticated AI, and robust high-temperature superconducting magnets. These innovations have enabled more advanced reactor designs, improved simulations, and complex control schemes. Further boosting confidence, a U.S. Department of Energy lab announced a groundbreaking achievement in late 2022: a controlled fusion reaction that produced more energy than the lasers imparted to the fuel pellet. This milestone, known as scientific breakeven, proved the underlying science, even as commercial breakeven (where the facility produces more energy than it consumes) remains a future goal. Founders have capitalized on this momentum, accelerating the private fusion industry's progress.

Let's look at the fusion startups that have raised over $100 million:

Commonwealth Fusion Systems

Commonwealth Fusion Systems (CFS) has secured approximately one-third of all private capital invested in fusion companies globally. Its latest funding round, which closed in August, added $863 million, bringing its total raised to nearly $3 billion. This Series B2 round followed its $1.8 billion Series B, solidifying CFS's leading position in the sector. The Massachusetts-based startup is actively constructing Sparc, its pioneering power plant designed to generate power at "commercially relevant" levels.

Sparc utilizes a tokamak design, resembling a doughnut. Its D-shaped cross-section is wrapped with high-temperature superconducting tape, which, when energized, creates a powerful magnetic field to contain and compress superheated plasma. The heat generated is then converted into steam to power a turbine. CFS developed its magnets in collaboration with MIT, where co-founder and CEO Bob Mumgaard conducted research on fusion reactor designs and high-temperature superconductors.

CFS anticipates Sparc becoming operational in late 2026 or early 2027. Later this decade, the company plans to commence construction on Arc, its commercial power plant, which will produce 400 megawatts of electricity. This facility will be located near Richmond, Virginia, and Google has committed to purchasing half of its output. Notable investors backing CFS include Breakthrough Energy Ventures, The Engine, and Bill Gates.

TAE Technologies

Founded in 1998 by Norman Rostoker, a spin-out from the University of California, Irvine, TAE Technologies (formerly Tri Alpha Energy) employs a field-reversed configuration. Uniquely, after two plasma shots collide in the reactor's center, the company bombards the plasma with particle beams, maintaining a stable, cigar-shaped spin. This enhances plasma stability, allowing more time for fusion and greater heat extraction for turbine power generation.

In December 2025, TAE announced a merger with Trump Media & Technology Group, President Donald Trump's social media company. This all-stock transaction valued the combined entity at $6 billion, with TAE set to receive $200 million initially and an additional $100 million upon SEC filing. TAE CEO Michl Binderbauer will serve as co-CEO alongside Devin Nunes, former sole CEO of Trump Media.

Prior to the merger, TAE had raised $150 million in June from existing investors, including Google, Chevron, and New Enterprise. According to PitchBook, TAE's total funding before the merger stood at $1.79 billion.

Helion

Among fusion startups, Helion boasts the most ambitious timeline, aiming to produce electricity from its reactor by 2028, with Microsoft as its inaugural customer. Based in Everett, Washington, Helion utilizes a field-reversed configuration reactor. This design features magnets encircling an hourglass-shaped reaction chamber, with a bulge where the two sides meet. Plasma is spun into doughnut shapes at each end of the hourglass and then propelled towards each other at over 1 million mph. Upon collision in the center, additional magnets induce fusion. The resulting fusion boosts the plasma’s magnetic field, generating an electrical current within the reactor’s magnetic coils, which is then harvested directly.

The company raised $425 million in January 2025, coinciding with the activation of Polaris, its prototype reactor. PitchBook reports Helion's total funding at $1.03 billion, with investors including Sam Altman, Reid Hoffman, KKR, BlackRock, Peter Thiel’s Mithril Capital Management, and Capricorn Investment Group.

Pacific Fusion

Pacific Fusion made a dramatic entrance with a $900 million Series A round, a substantial sum even for well-funded fusion startups. The company plans to achieve fusion through inertial confinement, but instead of lasers, it will use coordinated electromagnetic pulses to compress the fuel. The critical challenge lies in the precise timing: 156 impedance-matched Marx generators must simultaneously deliver 2 terawatts for 100 nanoseconds, converging on the target.

Led by CEO Eric Lander, who spearheaded the