- Set 2 Winner: Kostyuk vs Stephens81¢
- Kostyuk vs. Stephens: Set 1 Games O/U 8.559¢
- Kostyuk vs. Stephens: Set 2 Games O/U 9.550¢
- Set Handicap: Kostyuk (-1.5) vs Stephens (+1.5)66¢
- Kostyuk vs. Stephens: Set 1 Games O/U 9.550¢
- Kostyuk vs. Stephens: Set 1 Games O/U 10.520¢
- Kostyuk vs. Stephens: Set 2 Games O/U 10.550¢
- Game Spread: Kostyuk (-5.5) vs Stephens (+5.5)53¢
- Kostyuk vs. Stephens: Match O/U 22.536¢
- US Open WTA: Marta Kostyuk vs Sloane Stephens87¢
- US Open WTA: Completed Match: Marta Kostyuk vs Sloane Stephens50¢
- Kostyuk vs. Stephens: Match O/U 21.538¢
This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the US Open WTA, originally scheduled for September 2, 2026 at 11:00AM ET. This market will resolve to 'Marta Kostyuk' if Marta Kostyuk advances against Sloane Stephens. This market will resolve to 'Sloane Stephens' if Sloane Stephens advances against Marta Kostyuk. If the match is canceled (not played at all), ends in a tie, or a winner has not been determined by September 16, 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 WTA Tour. A consensus of credible reporting may also be used.
Marta Kostyuk, the No. 11 seed and world No. 11, enters the US Open second round after a strong 2026 season that includes French Open and Wimbledon semifinals plus multiple titles, while holding a recent straight-sets win over Sloane Stephens in Cincinnati. Stephens, a 2017 US Open champion ranked outside the top 200, earned a wild card and notched her first Grand Slam victory in two years by defeating Clara Tauson in the opener, benefiting from home-crowd support on hard courts. Their head-to-head favors Kostyuk, though Stephens has shown improved form on American hard courts this summer. The matchup highlights Kostyuk’s consistent baseline power and movement against Stephens’ experience and potential for elevated play in New York.