It’s a joke but it’s also essentially how binary prediction markets work: you have two contracts, each of which resolves to $1 or $0 depending (oppositely) on w

It’s a joke but it’s also essentially how binary prediction markets work: you have two contracts, each of which resolves to $1 or $0 depending (oppositely) on whether X happens. You then solicit bids on both. When the sum of the offer price of both exceeds $1, you sell one of each, and put the dollar you collect aside to pay out to whichever bet comes true.