Thin markets, big risks: Uranium supply concentration in the age of AI and nuclear expansion

Uranium markets play a critical role in the expansion of nuclear power but remain structurally vulnerable to volatility. This study quantifies the relationship between supply concentration, contracting structures, and uranium spot price dynamics over the period 2015 to 2024. Using global mine production data, supply concentration is shown to remain persistently high, with the leading producer accounting for 38-46% of global output and Herfindahl–Hirschman Index values consistently exceeding 2700. Quantile regression results reveal strong nonlinear effects, with spot price elasticity to concentration rising from 0.63 at the median to 1.94 at the 90th percentile. A two-state regime-switching model identifies a high-volatility regime with price volatility three times higher than in stable periods and an average duration exceeding 14 months. Interaction models further show that a one percentage point reduction in spot market share increases volatility by approximately 1.6%. These findings illustrate that uranium price volatility is structural rather than episodic, driven by concentrated supply and thin liquidity in the spot market. • This studyassess the structural features of uranium markets by examining supply concentration. • Uranium supply is highly concentrated, with the leading producer accounting for 38–46% of global output. • HHI values consistently exceeding 2700 confirm a structurally non-competitive market. • Widespread long-term contracting limits spot-market depth, weakening liquidity and price discovery.