[r00fus]

Problem with your idea (which is conceptually valid) is that you can buy and sell on Predictit well before the closure of the "market/event". So many people who agreed with a politician or idea (that some event would happen) would still sell early (at 90c/1$) because they could use those funds in other markets.

Worse still - you have people who would pump & dump the market - pushing the contra position (Trump wins 2020) and post comments showing showing holdings supporting contra, and then dump after it gains a significant share. I've heard of some predictit users doing this same operation 5x or more on a single market (an iconic example: Iowa Dem Primary 2020).

So it's all speculation.