This market is about the January 6th case against Trump.
Per Politico, Donald Trump wants to delay the case as much as possible, ideally past the election. It seems to me that one of the best things that could happen for him would be for the case to be declared a mistrial. Per Wikipedia:
A judge may cancel a trial prior to the return of a verdict; legal parlance designates this as a "mistrial".
A judge may declare a mistrial due to:
The court determining that it lacks jurisdiction over a case.
Evidence being admitted improperly, or new evidence that might seriously affect the outcome of the trial being discovered.
Misconduct by a party, juror,or an outside actor, if it prevents due process.
A hung jury which cannot reach a verdict with the required degree of unanimity. In a criminal trial, if the jury is able to reach a verdict on some charges but not others, the defendant may be retried on the charges that led to the deadlock, at the discretion of the prosecution.
Disqualification of a juror after the jury is empaneled, if no alternative juror is available and the litigants do not agree to proceed with the remaining jurors, or the remaining jurors not meeting the required number for a trial.
The illness or death of a juror or attorney.
Attempting to change a plea during an ongoing trial, which normally is not allowed.
Either side may submit a motion for a mistrial; on occasion, the presiding judge may declare one on a motion of their own. If a mistrial is declared, the case at hand may be retried at the discretion of the plaintiff or prosecution, as long as double jeopardy does not bar that party from doing so.
In particular, one can imagine that in such a polarized political environment the jury may simply be unable to reach a unanimous verdict. A single stubborn partisan could disagree with the rest of the jury and create a deadlock. But a mistrial could also be declared for other reasons like those listed above.
If a mistrial is declared in this case prior to election day, this market resolves Yes. Otherwise, it resolves No.