Advanced reactor company that achieved criticality with its Mark-0 microreactor on June 4, 2026 at Idaho National Laboratory. First privately developed non-light-water reactor to reach criticality in the US in over 40 years. Part of DOE Reactor Pilot Program. Antares is developing a compact HTGR microreactor selected for both the DOE Reactor Pilot Program (targeting July 4, 2026 criticality at INL) and the DoD Advanced Nuclear Power for Installations programme (April 2025); the dual civilian DOE and military DoD programme support positions it as one of the most broadly backed US microreactor developers, and it targets military base energy security and remote industrial applications. (Founded in 2023, confirmed by ANS Nuclear News and NEI Magazine in June 2026; an earlier record said 2020.)
Caffeinated Capital; Humba Ventures; Pathbreaker; Rogue VC; Shrug; Uncommon Capital; Alt Cap; Banter Capital; Box Group; Shine Capital; Paradigm; Point72 Ventures; Industrious Ventures