History. 5 of 5. States filed on day 0, day 1 and 7 days early in the three cases they led, and on day 29 and day 36 when groups went first.
Hunch.
The states market resolves on the attorneys general's press releases and the court records in CourtListener: YES if one or more US states file a court challenge to the rule by 30 November 2026. If the rule has not appeared in the Federal Register by 9 October 2026 the market is void, and Reuters and AP reports are the backup.
We looked for cases where a new US government cancelled or weakened a binding rule made under a government of the other party, and opponents said in public, before the new rule came out, that they would go to court. We found five such cases, all since 2018. In every one, the first court challenge was filed by the day after the rule appeared in the Federal Register.