Analysis
Antares, a nuclear startup building small modular reactors for US military installations, raised a $470 million Series C -- $370 million in equity and $100 million in debt -- led by Paradigm and Caffeinated Capital, with Industrious Ventures, Point72 Ventures and Shine Capital also participating. The round brings the three-year-old company's total funding past $600 million.
Antares' reactor design produces between 100 kilowatts and 1 megawatt using TRISO fuel, which encapsulates uranium in carbon and ceramic shells for added safety margin. The company is one of three finalists in the Pentagon's Advanced Nuclear Power for Installations program, which will pilot small modular reactors on Air Force bases in Colorado and Montana -- a real government testbed rather than a hypothetical pipeline. Competitors in the military and commercial SMR space include Oklo, X-energy and Kairos Power, all racing similar timelines with varying reactor designs and funding levels.
“Antares' reactor design produces between 100 kilowatts and 1 megawatt using TRISO fuel, which encapsulates uranium in carbon and ceramic shells for added safety margin.”
The deadline pressure is real and externally imposed: President Trump's Executive Order 14299 requires the Department of Defense to begin operating a domestic reactor at a military installation by September 30, 2028, giving Antares and its competitors a hard government-set clock rather than an open-ended R&D runway. Antares is targeting first electricity generation from its own reactor next year, ahead of the military deployment timeline.
This round extends 2026's defense-tech funding boom -- a year that has also produced large rounds for space-security and military-cyber startups -- as venture firms increasingly treat national-security infrastructure as a category with real exit potential rather than a mission-driven side bet. A $470 million Series C for a pre-revenue nuclear hardware company would have been unthinkable in venture five years ago; it's now one of several similarly-sized defense-adjacent rounds this year alone.
What to watch: whether Antares hits its stated 2027 first-power target, how the Pentagon narrows its three-finalist SMR competition, and whether other VC-backed nuclear startups follow with comparably sized rounds as the 2028 EO deadline approaches.
