AI doom questions run into the fun issue that only one side of the market can get a payout, resulting in "free internet points!" bets on one side.
This question follows in the long tradition of trying to dodge that failure mode, by resolving only post singularity when we should have the technology to estimate the true p(doom) numbers. Trades will morally be worth the p(doom) on the day they are made, hopefully whatever manifold becomes post singularity will figure out the details of how to make those payouts a fairly. Else, "today's" will mean the day this is posted.
It will resolve N/A if somehow there is not enough negentropy in the lightcone to run the compute needed to estimate this to a reasonable degree of accuracy, and the deadline will be extended if we haven't hit a singularity by 2100.