A running tally of private fusion startups that have raised more than $100 million, tracking total capital raised, reactor designs, investors, and timelines. Commonwealth Fusion Systems leads with $3.94 billion raised, followed by Helion at $3.2 billion and TAE Technologies at $1.65 billion (before its merger with Trump Media). The list covers 16 companies pursuing varied approaches — tokamaks, stellarators, field-reversed configurations, and inertial confinement — including Pacific Fusion, Proxima Fusion, Shine Technologies, Inertia Enterprises, General Fusion, Zap Energy, Tokamak Energy, Focused Energy, Marvel Fusion, Type One Energy, Kyoto Fusioneering, First Light Fusion, Thea Energy, and Xcimer, noting funding rounds, valuations, key investors, and notable milestones or setbacks like General Fusion's layoffs and subsequent public listing.
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Commonwealth Fusion SystemsHelionTAE TechnologiesPacific FusionProxima FusionShine TechnologiesInertia EnterprisesGeneral FusionZap EnergyTokamak EnergyFocused EnergyMarvel FusionType One EnergyKyoto FusioneeringFirst Light FusionThea EnergyXcimerQuestions this post answers
How much money has Commonwealth Fusion Systems raised in total?
Commonwealth Fusion Systems has raised $3.94 billion in total private capital, about a third of all money invested in fusion companies to date. Its most recent round, closed in July, added $1 billion. The company is building Sparc, a tokamak reactor in Massachusetts expected to reach scientific breakeven around 2027, with Google agreeing to buy half the output of its planned commercial plant, Arc, near Richmond, Virginia. Track fusion funding rounds and reactor milestones as they happen on daily.dev.
What reactor design does Helion use and who is its first customer?
Helion uses a field-reversed configuration reactor, shaped like an hourglass, where doughnut-shaped plasma is shot from each end at over 1 million mph and collides in the middle to trigger fusion, with electricity harvested directly from induced current. Microsoft is its first customer, and Helion plans to produce electricity by 2028. The company has raised $3.2 billion total, including a $465 million Series G at a $15.5 billion valuation. Compare emerging fusion reactor designs and funding trajectories on daily.dev.
What happened to General Fusion after it ran short on cash in 2025?
General Fusion laid off 25% of its staff in spring 2025 after running short on cash while building its LM26 device. Investors later injected $22 million in a pay-to-play round, and the company raised another $51.1 million in SAFE notes. It then went public via a reverse merger, listing on the Nasdaq on July 13, 2026, netting $127 million. Follow how struggling deep-tech startups pivot to funding and public listings on daily.dev.