Yes. Although uncommon, a market may be cancelled if it cannot be resolved fairly or in accordance with its published rules.
This may happen if:
The underlying event is postponed or cancelled indefinitely.
The verification source becomes unavailable or cannot provide a definitive outcome.
The market question becomes ambiguous or can no longer be answered as written.
An unforeseen event prevents the market from being settled fairly.
If a market is cancelled, Signal will notify affected users.