At market close, everyone who holds at least one share (in either direction) gets to vote for YES or NO. This market resolves based on the outcome of that vote. (One vote per person.)

If the vote is tied or close to tied, I'll wait a while to see if anyone wants to change their vote. (If necessary instituting a time limit before the vote becomes final.) If it ends up being exactly even and no one wants to change their vote, I'll resolve to 50%.