Atlas Atomics raises $400M at $1.9B valuation

What did Atlas Atomics raise, and what do reports say about the deal?

Atlas Atomics reportedly raised about $400 million in fresh capital in a Series A round that valued the stealth nuclear startup at approximately $1.9 billion. Bloomberg published the report on Oct. 8, 2026, and said the financing details came from people familiar with the matter who declined to be identified because the information was private.

Investing.com reported the same broad terms, saying Atlas Atomics raised $400 million in a Series A at a $1.9 billion valuation. Axios later repeated Bloomberg’s account in a climate and energy deals roundup, describing it as an ongoing Series A.

Bloomberg also described Atlas Atomics as a nuclear startup cofounded and backed by Vivek Ramaswamy. The company has not publicly confirmed the financing, and the report said the transaction remained private at the time.

Who backed the round?

Bloomberg said General Catalyst led the financing and that Andreessen Horowitz participated. Investing.com also identified General Catalyst as the lead investor and Andreessen Horowitz as a participant.

Energy Connects said Atlas Atomics, General Catalyst and Andreessen Horowitz declined to comment on the reported financing, and Entrepreneur India repeated that account. Those non-responses mean the deal details remain based on reporting rather than company confirmation.

The financing fits into a broader surge in nuclear startup funding that Energy Connects said has accelerated this year. The publication reported that investors had poured $4.6 billion into U.S. nuclear startups in 2026, alongside a presidential push to expand atomic power.

What is Atlas Atomics building?

Atlas Atomics is a U.S.-based nuclear startup that was still in stealth mode at the time of the report. Energy Connects said the company is led by cofounder Kevin Gan, who spent more than 15 years investing in energy companies and most recently worked at Millennium after earlier roles at D.E. Shaw & Co.

The company’s chief nuclear officer is Balendra Sutharshan, who previously served as chief operating officer of Oak Ridge National Laboratory. According to Energy Connects, Atlas is developing improved heavy water reactor technology that does not rely on enriched uranium and may therefore be cheaper.

Gan said in a letter to the Utah Governor’s Office of Energy Development that Atlas’s goals for the technology are to deliver reliable power, create more production of medical and industrial isotopes, and support recycling of nuclear fuel. Those aims suggest the startup is positioning its reactors for both grid power and industrial applications.

Why does the startup matter now?

Energy Connects said President Donald Trump signed an executive order to quadruple U.S. nuclear capacity by 2050, a policy backdrop that has helped fuel investor interest. In the same report, it cited Antares Nuclear Inc.’s $470 million summer raise to build small reactors for U.S. military bases and Sequoia Capital’s $1 billion funding round for Valar Atomics Inc.

Atlas Atomics’ reported financing would place it among the larger recent deals in the sector if completed as described. The combination of a large round, a high valuation and a stealth profile suggests investors are betting early on the company’s reactor technology and on demand for new nuclear supply chains.

Even so, the story remains an unconfirmed reported financing. Atlas Atomics, General Catalyst and Andreessen Horowitz did not publicly discuss the transaction in the reporting cited here, and the company’s broader plans are still being described through third-party accounts and a letter Gan sent to Utah officials.