This market refers to the doubles tennis match between Guo/Mladenovic and Hsieh/Ostapenko in the WTA Finals Doubles, Group 1, originally scheduled for November 9, 2026 at 7:30PM ET. This market will resolve to 'Guo/Mladenovic' if the team of Guo/Mladenovic advances against Hsieh/Ostapenko. This market will resolve to 'Hsieh/Ostapenko' if the team of Hsieh/Ostapenko advances against Guo/Mladenovic. If the match is canceled (not played at all), ends in a tie, or a winner has not been determined by November 23, 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 team advances due to the opponent's retirement, default, or disqualification, this market will resolve to the team who advances. If the match ends in a walkover (a team 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 WTA Tour. A consensus of credible reporting may also be used.