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Sports·WTA Tour

Marta Kostyuk – Sloane Stephens

1d 7h
Polymarket
Aug 18·2:00 PM
M. KostyukM. Kostyuk
-
S. StephensS. Stephens
-
$10.00 Vol.Polymarket
NEW

Moneyline

$10 Vol.

This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM 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 is delayed beyond 7 days from the scheduled date without a winner determined, 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.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Yes" if all games and sets required to determine a match winner under governing body or event organizer rules are played to completion through normal play. Otherwise, if the match is not completed for any reason, it will resolve to "No." If a forfeit of any kind occurs, including but not limited to a walkover or retirement, this market will resolve "No." If the match is canceled (not played at all), ends in a tie, or is delayed beyond 7 days from the scheduled date without a winner determined, this market will resolve to "No." The primary resolution source for this market is the official statistics of the event as recognized by the governing body or event organizers. However, if the governing body or event organizers have not published final match statistics within 2 hours after the event's conclusion, a consensus of credible reporting may be used instead.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to “Kostyuk” if Marta Kostyuk wins set 2. It will resolve to “Stephens” if Sloane Stephens wins set 2. If the match begins but set 2 is not completed with a winner determined (including the match ending before set 2 is reached), this market will resolve 50-50. If the match is canceled (not played at all) or is delayed beyond 7 days from the scheduled date without play beginning, this market will resolve 50-50. Resolution will be based on official WTA match statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to “Kostyuk” if Marta Kostyuk wins the first set. It will resolve to “Stephens” if Sloane Stephens wins the first set. If the match begins but is not completed, and the first set is concluded with a winner determined, this market will resolve based on that completed set. If the first set is not completed for any reason, this market will resolve 50-50. If the match is canceled (not played at all) or is delayed beyond 7 days from the scheduled date without play beginning, this market will resolve 50-50. Resolution will be based on official WTA match statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of sets completed equals or exceeds 3. Otherwise, it will resolve to "Under." A super tie breaker is considered as one (1) set for total set markets. If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed across all sets equals or exceeds 22. Otherwise, it will resolve to "Under." All tiebreaks—including any Champions/Super tiebreak—count as one (1) game toward the total. If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Kostyuk" if Marta Kostyuk wins by 2 or more sets than Sloane Stephens, based on the final completed score. Otherwise, it will resolve to "Stephens." If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed across all sets equals or exceeds 23. Otherwise, it will resolve to "Under." All tiebreaks—including any Champions/Super tiebreak—count as one (1) game toward the total. If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed across all sets equals or exceeds 24. Otherwise, it will resolve to "Under." All tiebreaks—including any Champions/Super tiebreak—count as one (1) game toward the total. If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in the first set equals or exceeds 9. Otherwise, it will resolve to "Under." Any first-set tiebreak counts as one (1) game toward the total. If the first set is not completed for any reason, this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in set 2 equals or exceeds 9. Otherwise, it will resolve to "Under." Any tiebreak in set 2 counts as one (1) game toward the total. If set 2 is not completed for any reason (including the match ending before set 2 is reached), this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in the first set equals or exceeds 10. Otherwise, it will resolve to "Under." Any first-set tiebreak counts as one (1) game toward the total. If the first set is not completed for any reason, this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in set 2 equals or exceeds 10. Otherwise, it will resolve to "Under." Any tiebreak in set 2 counts as one (1) game toward the total. If set 2 is not completed for any reason (including the match ending before set 2 is reached), this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in the first set equals or exceeds 11. Otherwise, it will resolve to "Under." Any first-set tiebreak counts as one (1) game toward the total. If the first set is not completed for any reason, this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in set 2 equals or exceeds 11. Otherwise, it will resolve to "Under." Any tiebreak in set 2 counts as one (1) game toward the total. If set 2 is not completed for any reason (including the match ending before set 2 is reached), this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.Marta Kostyuk enters the second-round matchup at the 2026 Cincinnati Open as the clear favorite, riding a career-high ranking of No. 11 and a strong 2026 record near 29-7. The Ukrainian has built momentum with clay-court titles in Madrid and Rouen plus a Roland Garros semifinal, while showing positive hard-court adaptation by defeating Madison Keys in Toronto before falling to Iga Swiatek. Sloane Stephens, ranked around No. 240 with a 2026 mark near .500, brings veteran experience and home-crowd support in her record 13th Cincinnati appearance, but has posted inconsistent results this season and relies on grinding out wins despite subpar form. The hard-court surface favors Kostyuk’s current athletic baseline game and recent consistency over Stephens’ variable output.

This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM 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 is delayed beyond 7 days from the scheduled date without a winner determined, 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.
Volume
$10
End Date
Aug 25, 2026
Market Opened
Aug 17, 2026, 12:14 AM ET

Resolution Source

https://www.wtatennis.com/scores

Resolver

0x65070BE91...
This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM 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 is delayed beyond 7 days from the scheduled date without a winner determined, 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.

Beware of external links.

Frequently Asked Questions

The “S. Stephens vs. M. Kostyuk” market on Polymarket lets you trade on the outcome of the WTA Tour game between the Sloane Stephens and the Marta Kostyuk, scheduled for August 18, 2026 at 10:00 AM ET. The primary market is the moneyline — which team will win the game — where M. Kostyuk is currently priced at 84¢ (84% implied probability) and S. Stephens at 16¢ (16%). Beyond the moneyline, sports markets on Polymarket may feature spreads, totals (over/under), and player props, giving you multiple ways to trade on this game. Prices reflect real-time crowd-sourced probabilities. Shares in the correct outcome pay out $1 each when the market resolves after the game ends.

As of now, the “S. Stephens vs. M. Kostyuk” market has generated $10 in total trading volume across all market types (moneyline, spreads, totals, and player props). This volume reflects active engagement from the Polymarket trading community, and a deeper pool of traders generally means more informative, reliable odds. You can track live price movements and trade on any market directly on this page.

To trade on “S. Stephens vs. M. Kostyuk,” start by choosing the market type you want to trade: Moneyline (which team wins), Spreads (margin of victory), Totals (combined score over/under), or Player Props (individual player stat lines). Each market shows the current price for each side — for example, the moneyline shows STEPHEN at 16¢ and KOSTYUK at 84¢. Select the side you want to trade, choose Buy to take a position or Sell to close an existing one, enter your amount, and click Trade. If your chosen side is correct when the game ends and the market resolves, your shares pay out $1 each. If it’s incorrect, they pay out $0. You can also sell your shares at any time before the game ends to lock in a profit or cut a loss.

The current moneyline odds for “S. Stephens vs. M. Kostyuk” show Marta Kostyuk at 84¢ (84% implied probability) and Sloane Stephens at 16¢ (16%). All odds update in real-time as traders buy and sell shares, reflecting the latest collective view of how this game will play out. Check back frequently or bookmark this page to follow how the odds shift as game time approaches.

The “S. Stephens vs. M. Kostyuk” market resolves based on the official final score of the WTA Tour game as reported by WTA Tour’s official results, including overtime if applicable. Moneyline markets resolve to the team that wins the game. Spread markets resolve based on the final margin of victory relative to the posted line. Totals (over/under) markets resolve based on the combined final score of both teams. Player prop markets resolve based on official box score statistics. If the game is postponed or canceled, the market resolution rules (available in the Rules section on this page) specify how that scenario is handled. We recommend reviewing the full resolution criteria before trading.
Sports·WTA Tour

Marta Kostyuk – Sloane Stephens

1d 7h
Polymarket
Aug 18·2:00 PM
M. KostyukM. Kostyuk
-
S. StephensS. Stephens
-
$10.00 Vol.Polymarket
NEW

Moneyline

$10 Vol.

This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM 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 is delayed beyond 7 days from the scheduled date without a winner determined, 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.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Yes" if all games and sets required to determine a match winner under governing body or event organizer rules are played to completion through normal play. Otherwise, if the match is not completed for any reason, it will resolve to "No." If a forfeit of any kind occurs, including but not limited to a walkover or retirement, this market will resolve "No." If the match is canceled (not played at all), ends in a tie, or is delayed beyond 7 days from the scheduled date without a winner determined, this market will resolve to "No." The primary resolution source for this market is the official statistics of the event as recognized by the governing body or event organizers. However, if the governing body or event organizers have not published final match statistics within 2 hours after the event's conclusion, a consensus of credible reporting may be used instead.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to “Kostyuk” if Marta Kostyuk wins set 2. It will resolve to “Stephens” if Sloane Stephens wins set 2. If the match begins but set 2 is not completed with a winner determined (including the match ending before set 2 is reached), this market will resolve 50-50. If the match is canceled (not played at all) or is delayed beyond 7 days from the scheduled date without play beginning, this market will resolve 50-50. Resolution will be based on official WTA match statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to “Kostyuk” if Marta Kostyuk wins the first set. It will resolve to “Stephens” if Sloane Stephens wins the first set. If the match begins but is not completed, and the first set is concluded with a winner determined, this market will resolve based on that completed set. If the first set is not completed for any reason, this market will resolve 50-50. If the match is canceled (not played at all) or is delayed beyond 7 days from the scheduled date without play beginning, this market will resolve 50-50. Resolution will be based on official WTA match statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of sets completed equals or exceeds 3. Otherwise, it will resolve to "Under." A super tie breaker is considered as one (1) set for total set markets. If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed across all sets equals or exceeds 22. Otherwise, it will resolve to "Under." All tiebreaks—including any Champions/Super tiebreak—count as one (1) game toward the total. If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Kostyuk" if Marta Kostyuk wins by 2 or more sets than Sloane Stephens, based on the final completed score. Otherwise, it will resolve to "Stephens." If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed across all sets equals or exceeds 23. Otherwise, it will resolve to "Under." All tiebreaks—including any Champions/Super tiebreak—count as one (1) game toward the total. If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed across all sets equals or exceeds 24. Otherwise, it will resolve to "Under." All tiebreaks—including any Champions/Super tiebreak—count as one (1) game toward the total. If the match begins but is not completed, this market will resolve 50-50. If the match is canceled before play begins or delayed beyond 7 days from the scheduled date without a result, this market will also resolve 50-50. Resolution will be based on official WTA statistics.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in the first set equals or exceeds 9. Otherwise, it will resolve to "Under." Any first-set tiebreak counts as one (1) game toward the total. If the first set is not completed for any reason, this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in set 2 equals or exceeds 9. Otherwise, it will resolve to "Under." Any tiebreak in set 2 counts as one (1) game toward the total. If set 2 is not completed for any reason (including the match ending before set 2 is reached), this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in the first set equals or exceeds 10. Otherwise, it will resolve to "Under." Any first-set tiebreak counts as one (1) game toward the total. If the first set is not completed for any reason, this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in set 2 equals or exceeds 10. Otherwise, it will resolve to "Under." Any tiebreak in set 2 counts as one (1) game toward the total. If set 2 is not completed for any reason (including the match ending before set 2 is reached), this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in the first set equals or exceeds 11. Otherwise, it will resolve to "Under." Any first-set tiebreak counts as one (1) game toward the total. If the first set is not completed for any reason, this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM ET. This market will resolve to "Over" if the total number of games completed in set 2 equals or exceeds 11. Otherwise, it will resolve to "Under." Any tiebreak in set 2 counts as one (1) game toward the total. If set 2 is not completed for any reason (including the match ending before set 2 is reached), this market will resolve 50-50. If the match is canceled before play begins, or delayed beyond 7 days without commencement, this market will also resolve 50-50. Resolution will be based on official WTA results.Marta Kostyuk enters the second-round matchup at the 2026 Cincinnati Open as the clear favorite, riding a career-high ranking of No. 11 and a strong 2026 record near 29-7. The Ukrainian has built momentum with clay-court titles in Madrid and Rouen plus a Roland Garros semifinal, while showing positive hard-court adaptation by defeating Madison Keys in Toronto before falling to Iga Swiatek. Sloane Stephens, ranked around No. 240 with a 2026 mark near .500, brings veteran experience and home-crowd support in her record 13th Cincinnati appearance, but has posted inconsistent results this season and relies on grinding out wins despite subpar form. The hard-court surface favors Kostyuk’s current athletic baseline game and recent consistency over Stephens’ variable output.

This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM 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 is delayed beyond 7 days from the scheduled date without a winner determined, 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.
Volume
$10
End Date
Aug 25, 2026
Market Opened
Aug 17, 2026, 12:14 AM ET

Resolution Source

https://www.wtatennis.com/scores

Resolver

0x65070BE91...
This market refers to the tennis match between Marta Kostyuk and Sloane Stephens in the Cincinnati Open, originally scheduled for August 18, 2026 at 10:00AM 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 is delayed beyond 7 days from the scheduled date without a winner determined, 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.

Beware of external links.

Frequently Asked Questions

The “S. Stephens vs. M. Kostyuk” market on Polymarket lets you trade on the outcome of the WTA Tour game between the Sloane Stephens and the Marta Kostyuk, scheduled for August 18, 2026 at 10:00 AM ET. The primary market is the moneyline — which team will win the game — where M. Kostyuk is currently priced at 84¢ (84% implied probability) and S. Stephens at 16¢ (16%). Beyond the moneyline, sports markets on Polymarket may feature spreads, totals (over/under), and player props, giving you multiple ways to trade on this game. Prices reflect real-time crowd-sourced probabilities. Shares in the correct outcome pay out $1 each when the market resolves after the game ends.

As of now, the “S. Stephens vs. M. Kostyuk” market has generated $10 in total trading volume across all market types (moneyline, spreads, totals, and player props). This volume reflects active engagement from the Polymarket trading community, and a deeper pool of traders generally means more informative, reliable odds. You can track live price movements and trade on any market directly on this page.

To trade on “S. Stephens vs. M. Kostyuk,” start by choosing the market type you want to trade: Moneyline (which team wins), Spreads (margin of victory), Totals (combined score over/under), or Player Props (individual player stat lines). Each market shows the current price for each side — for example, the moneyline shows STEPHEN at 16¢ and KOSTYUK at 84¢. Select the side you want to trade, choose Buy to take a position or Sell to close an existing one, enter your amount, and click Trade. If your chosen side is correct when the game ends and the market resolves, your shares pay out $1 each. If it’s incorrect, they pay out $0. You can also sell your shares at any time before the game ends to lock in a profit or cut a loss.

The current moneyline odds for “S. Stephens vs. M. Kostyuk” show Marta Kostyuk at 84¢ (84% implied probability) and Sloane Stephens at 16¢ (16%). All odds update in real-time as traders buy and sell shares, reflecting the latest collective view of how this game will play out. Check back frequently or bookmark this page to follow how the odds shift as game time approaches.

The “S. Stephens vs. M. Kostyuk” market resolves based on the official final score of the WTA Tour game as reported by WTA Tour’s official results, including overtime if applicable. Moneyline markets resolve to the team that wins the game. Spread markets resolve based on the final margin of victory relative to the posted line. Totals (over/under) markets resolve based on the combined final score of both teams. Player prop markets resolve based on official box score statistics. If the game is postponed or canceled, the market resolution rules (available in the Rules section on this page) specify how that scenario is handled. We recommend reviewing the full resolution criteria before trading.