Market resolves when the bid is awarded by the IOC. (I'm not waiting another ~7 years just in case things change).
Market resolves to one answer, the exact country or set of countries awarded the games, this market will resolve to one entry. If the games are awarded to a joint Germany-Israel bid, neither "Germany" and "Israel" would be the answer, only "Germany & Israel" (in either order, that doesn't matter).
As the date of the election is not yet set, I made a guess (2026 Winter Games), and will close earlier or extend as necessary.
I added Chile, per https://en.wikipedia.org/wiki/Bids_for_the_2036_Summer_Olympics
Per that page, Poland and Mexico have withdrawn, and China seems to have done so as well.
I initially created the countries with confirmed bids per https://en.wikipedia.org/wiki/Bids_for_the_2036_Summer_Olympics.