Datacenter-power enthusiasm reversed with the AI trade — uranium developers and SMR names fell 4-8%, Denison the laggard at -7.8% — while naval-nuclear prime Huntington Ingalls rose 1.7%.

Huntington Ingalls (HII) led the nuclear basket, up 1.7% to $265.02. The vertical has traded as a leveraged bet on datacenter power demand, so when a Financial Times report that OpenAI's annualized revenue was running near $50bn — below the roughly $70bn investors expected — cracked the AI-capex trade, the AI-power read-through reversed with it. The exception was HII, the naval-nuclear shipbuilding prime (carriers and submarines), whose cash flows are a defense-budget line insulated from the AI thesis and bid in the day's rotation toward government-funded names. BWX Technologies (BWXT), the reactor-component chokepoint that spans both naval and small-modular work, held near flat, up 0.5% to $142.22.

The laggard was Denison Mines (DNN), down 7.8% to $2.36, at the front of a fuel-cycle selloff. Mining, conversion and enrichment — the physical fuel chokepoint — carry the most beta to the datacenter-demand narrative, so they led the retreat: enCore Energy (EU) −6.5% to $1.01, Uranium Energy (UEC) −3.5%, Centrus Energy (LEU) −3.4% to $142.09 on the enrichment rung, and the more mature Cameco (CCJ) −2.2% to $87.12. No fuel-market news drove the move; it was the AI-power trade coming off, compounded by higher-rate pressure on the pre-cash-flow developers.

The small-modular reactor developers — the rung betting on behind-the-meter contracts to power datacenters directly — fell hardest: Oklo (OKLO) −6.1% to $34.57, NuScale Power (SMR) −4.6% to $7.32, NANO Nuclear (NNE) −4.7% to $15.26, and X-Energy (XE) −4.3% to $13.77. The operating nuclear utilities closest to actual datacenter power-purchase agreements sold too: Vistra (VST) −6.3% to $156.14, Constellation Energy (CEG) −4.8% to $285.07, and Talen Energy (TLN) −5.0% to $359.22. The pattern was uniform — the more a name's valuation rides on the AI-datacenter power thesis, the harder it came off.

The next catalysts sit on the component and policy rungs. BWX Technologies reports Q3 around Nov 2 (estimated), the cleanest read on naval and SMR component backlog. On policy, definitive Westinghouse/US-government agreements replacing the binding term sheet are expected in the second half of 2026, and the NRC's decision on the Crane Clean Energy Center (the Three Mile Island Unit 1 restart tied to a datacenter power-purchase agreement) is expected in 2027 — the single hardest datacenter-power catalyst for Constellation on the calendar.