Peaceful & democratic: freely resigning, handing over the presidency to someone else, conceding defeat in an election.
Non-peaceful / non-democratic: death, imprisonment, coerced into resigning, defeat in an election/decision he contests, Ukraine ceasing to exist.
Whether an election result is "contested" will depend on Zelenskyy's official response. If his supporters contest a result but he accepts it, this will count as uncontested.
Re-election would not count as the end of his tenure.
The market will close when Zelenskyy ceases to be president of Ukraine.
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@Boklam I didn't think of that one. I'd resolve NO for not being democratic. By "handing over to someone else" I was trying to anticipate handing over to his deputy, say, in circumstances which would not legally require an election.
@StanPinsent So if the local laws never require elections, and they just peacefully pass power from one person to another ad infinitum...? (Like China, for example...)
I'm guessing I'm being too pedantic here. I think what you really mean is something like... when Z. leaves office, you're going to decide whether it looks like it happened according to procedure, like it would in a Western democracy, and use your judgement. Is this about right?
@Boklam pretty much. It has to be an election or a non-shady resignation to count as peaceful democratic transition.