Nuclear Energy in Transition: Are NUC Index Returns More Strongly Associated with AI-Related Equities than with an Energy Commodity Benchmark?

The growth in electricity demand driven by artificial intelligence and digital infrastructure is directing attention toward nuclear energy as a stable source. The sector has been transformed by the emergence of SMRs and the growing number of publicly listed developers. The aim of this paper is to investigate whether the stock returns of publicly listed SMR companies are more closely associated with the AI-related equity benchmark or with the energy commodity benchmark. Due to the absence of a unified SMRs index, a market-capitalization-weighted synthetic NUC index was constructed from Oklo Inc., NuScale Power Corporation, and NANO Nuclear Energy Inc. for the period from 1 July 2024 to 1 July 2026. The Global X Artificial Intelligence & Technology ETF (AIQ) and The S&P GSCI Energy Spot Index represented the AI-related equity and energy commodity benchmarks, respectively. The relationships were examined using correlation and regression analyses with Newey–West HAC standard errors, based on 501 daily logarithmic returns. NUC increased by 166.80%, versus 77.79% for AIQ and −7.68% for the energy benchmark. Correlations were 0.510 (p < 0.001) with AIQ and −0.059 (p = 0.186) with the energy benchmark; standardized coefficients were 0.509 and −0.046, respectively, differing significantly (one-sided p < 0.001).