Nuclear energy stocks jumped as investors digested the threat of DeepSeek. NANO Nuclear Energy rose 10%; NuScale Power rose 6%; Oklo rose 4%; Energy Fuels, Lightbridge, and Centrus rose 3%; Uranium, Vistra Energy, and Entergy rose 2%.

Shares of nuclear energy sold off on Monday in some of the biggest recorded one-day drops, as new AI technology from Chinese start-up DeepSeek cast doubt on a projected surge in U.S. electricity demand and tech spending.

Power producers were among the biggest winners in the S&P 500 last year on expectations of ballooning demand from the energy-guzzling data centers needed to scale Big Tech's artificial intelligence technologies.