The U.S. nuclear testing moratorium, in place since 1992, remains the central constraint on any near-term explosive test. Administration statements in late 2025 directed preparation to match alleged low-yield activity by China and Russia, and the fiscal 2026 defense authorization included provisions enabling underground tests at the Nevada National Security Site. As of September 2026, however, no test has occurred; officials continue to assess readiness timelines, which experts estimate at 18–36 months for a fully instrumented event. Congressional opposition, including the No Nuclear Testing Act, and concerns over treaty compliance and escalation have slowed momentum. Traders weigh these procedural, technical, and diplomatic hurdles against any future directive that could accelerate site preparation or subcritical experiments that fall short of a full-yield detonation.