On July 27, Antares Nuclear announced a $470 million Series C, cementing its position as one of the most highly capitalized startups in the advanced nuclear sector.

The round, co-led by Paradigm and Caffeinated Capital, with participation from Point72 Ventures, Shine Capital, and Industrious Ventures, pushes the company’s total funding past the $600 million mark. It also features a notable $100 million debt tranche.

Seven weeks before the raise, Antares became the first privately developed non-light-water reactor to reach criticality in the United States in more than 40 years. It did so on a government-only strategy, at a moment when most of its venture-backed peers went the opposite direction. While nearly every other venture-backed nuclear company of this generation is aggressively chasing AI data centers and hyperscalers, Antares is making a contrarian bet on the U.S. military.

With nuclear startups operating in a fiercely contested market, it raises a multi-billion-dollar question: is focusing on the Department of War—while peers lock up commercial tech giants—actually the best go-to-market strategy?