Mutually exclusive

Also called mutually_exclusive

Kalshi's flag for an event where at most one listed outcome can resolve YES — which is not the same as exactly one.

The gap between at most one and exactly one is small in English and large in money, and it is the reason the overround scanner treats the two venues differently.

When Kalshi marks an event mutually exclusive, it guarantees that no two listed outcomes can both resolve YES. It does not guarantee that one of them will. The listed set need not be exhaustive — an unlisted possibility can win and every listed leg resolves NO. So buying one NO of every leg still pays at least n − 1 dollars, and n if nothing listed wins, which means the ALL-NO direction remains a genuine lock. Buying one YES of every leg could pay nothing at all, so that direction is never surfaced for a Kalshi row no matter how cheap the legs look.

The flag is also used as the inclusion test itself: an event that does not carry it is skipped entirely rather than guessed at from the title. Polymarket's equivalent flag is stronger and permits both directions. If you take one thing from this entry, take the habit of asking whether a candidate list is exhaustive before you treat the sum of its prices as meaningful.

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Definitions describe how Polymarket and Kalshi behave and how WhaleTracks models them; venue rules and fee schedules can change, so confirm anything you size a position on with the venue itself. WhaleTracks is informational analytics, not financial advice. Past performance does not guarantee future results.