The United States has observed a voluntary moratorium on explosive nuclear testing since 1992, relying instead on subcritical experiments and the Science-Based Stockpile Stewardship Program at the Nevada National Security Site. Recent trader attention centers on statements from the Trump administration in 2025 directing preparations for possible resumption on an "equal basis" with adversaries, alongside diplomatic pressure on China over alleged low-yield or decoupled tests. In late September 2026, the National Nuclear Security Administration conducted a non-nuclear chemical high-explosive experiment in Nevada's P Tunnel to refine detection algorithms for concealed foreign blasts, explicitly framed as a monitoring effort rather than a step toward U.S. testing. No full-yield nuclear detonation has occurred, and resolution of any related market would depend on confirmation of an underground explosive test within the specified timeframe amid ongoing arms control discussions.