The following rules include reasons for voiding bets.
If a bet is placed after the relevant result or outcome is known, then the bet will be void.
In Outright markets all bets shall stand irrespective of whether the athlete competes or not (all-in run or not). If a swimmer withdraws before they have taken part in the event, the bet will be a loser.
Both swimmers must start an event, or all bets will be void.
All bets will be settled on the medal ceremony regardless of any subsequent disqualification. If there is no podium ceremony, settlement of bets will be based on the result declared by the official governing body FINA immediately after the event, irrespective of any subsequent enquiry.
This is determined by the country the winner competes for (not the country they were born in if there is a difference).