Every market shows its resolution source and rules before trading starts and they don’t change after launch. When the event concludes, the market resolves to the actual outcome.
Sources
Sports markets resolve automatically from official league scoring feeds. Politics, finance, and world-event markets resolve from the authoritative sources named in each market’s rules.
Void / N/A
If an event is cancelled, genuinely ambiguous, or its source fails, a market may resolve N/A. Open positions are then closed and settled at their current share price rather than forced to a wrong answer.