The U.S. has maintained a voluntary moratorium on nuclear explosive testing since 1992, relying instead on the Science-Based Stockpile Stewardship Program for stockpile confidence through simulation, subcritical experiments, and non-nuclear diagnostics. Recent developments include President Trump’s October 2025 directive to prepare testing “on an equal basis” with China and Russia amid allegations of Beijing’s covert low-yield activities, followed by administration clarifications that any resumed work would involve system tests or non-critical explosions rather than full-yield detonations. In late September 2026, the NNSA conducted a subsurface chemical high-explosive experiment at the Nevada National Security Site focused on improving detection of decoupled blasts, not on conducting a U.S. nuclear detonation. These factors, combined with long preparation timelines, Senate oversight, and diplomatic risks, underpin trader consensus assigning low implied probabilities to an explosive test by early 2026 deadlines. No site preparations for yield-producing tests have been confirmed.