From the ACX 2025 Prediction Contest:

Will resolve according to the Metaculus resolution:

This question resolves as Yes if at least one of the following occurs:

1. The Iranian government states that it has a nuclear weapon, and credible sources deem the statement to be credible.

2. The Iranian government states that it has tested a nuclear weapon at any time, and credible sources deem the statement to be credible.

3. At least one of these three sources, which will be considered per se authoritative for purposes of this question, reports that Iran possesses or has tested a nuclear weapon: the Arms Control Association, the Stockholm International Peace Research Institute and the Federation of American Scientists.

A "nuclear weapon" is defined as a device designed for military use that uses nuclear reactions to cause an explosion. Mere possession of weapons-grade uranium or development of related technology will not satisfy the resolution criteria.