Shares tied to nuclear power and uranium advanced on Monday after the U.S. Energy Secretary delivered upbeat comments about the prospects for small-modular reactors, traders said. Oklo Inc. and NuScale Power, both developing compact reactor technologies, led the gains, while uranium producer Cameco and the Global X Uranium ETF also rallied. Options-monitoring services flagged heavy call buying in URA as investors positioned for further strength in the sector. By contrast, Saiheat slipped despite receiving International Atomic Energy Agency approval in June to market its own small-modular reactor design, underscoring the divergence between larger and micro-cap players in the space. The market reaction highlights renewed investor interest in nuclear technology as governments look for low-carbon baseload power sources to meet decarbonisation targets.