This market refers to the tennis match between Stefanos Tsitsipas and Arthur Fils in the US Open ATP, originally scheduled for August 30, 2026 at 11:00AM ET. This market will resolve to 'Stefanos Tsitsipas' if Stefanos Tsitsipas advances against Arthur Fils. This market will resolve to 'Arthur Fils' if Arthur Fils advances against Stefanos Tsitsipas. If the match is canceled (not played at all), ends in a tie, or a winner has not been determined by September 13, 2026, 11:59 PM ET (14 days after the scheduled start), this market will resolve to 50-50. If the match begins but is not completed, and one player advances due to the opponent's retirement, default, or disqualification, this market will resolve to the player who advances. If the match ends in a walkover (player withdraws before the start and the other advances automatically), this market will resolve to 50-50. The primary resolution source will be official information from the ATP Tour. A consensus of credible reporting may also be used.