This resolves "yes" if there are at least two different candidates who both at any point satisfy at least one of the criteria listed in https://manifold.markets/ManifoldMarkets/will-there-be-a-robust-third-party and resolves "no" otherwise.

These candidates can be independent or affiliated with any party other than the Democratic and Republican parties. The criteria need not be met at the same time. For example, if candidate 1 is invited to one of the major-party presidential debates and then drops out, and then candidate 2 wins a state on election day, that counts. However, if two candidates run for the same third party at different times, or they have the same running mate or one was ever the other's running mate, I'll count them as a continuation of the same candidate. This is a little subjective, so I won't bet in this market.