Resolves once it's clear that either Trump is not running for the 3rd term (not going to try, or abandoned his attenmpt), or it's clear he was able to run without sufficient impediment to stop him.
If Trump does not try to run for a 3rd term, resolves NO
If Trump tries, but abandons the attempt before courts are involved, resolves NO
If Trump successfully runs for the 3rd term, resolves NO
A court decision that is overruled by a higher court does not count.
A successful 3rd term run resolves NO, even if he loses - even if there are some court decisions that prevented him from being on a ballot in some states.
State-specific court decisions count as a YES if they affect enough electoral votes to prevent him from being able to win even theoretically (and there were no other shenanigans that managed to bypass those decisions)
Court decision that is not followed, or otherwise bypassed (e.g. not on the ballot in state X, but state X legislature allocated electors to Trump in some other way) does not count.
If court decisions create barriers that are not necessary insurmountable, Trump later abandons his attempt, and the casual link is unclear - I will make a judgement call about the casual link.
Trump gives up after a court decision against him with a clear casual link - resolves YES
"Preventative" court case followed by Trump not trying - judgment call on the casual link.
Trump abandons or does not try due to multiple factors - as long as court decision(s) are a major factor (top factor, or among the top factors), resolves YES.
As this could end up being subjective, I will not trade this market.