Cincinnati Open: Marta Kostyuk vs Sloane Stephens

Q: Cincinnati Open: Marta Kostyuk vs Sloane Stephens

Prediction markets currently price this at 86%. A YES share costs 86.0¢ and pays $1 if it happens. That is a return of 16.3% over 8d.

Cincinnati Open: Marta Kostyuk vs Sloane Stephens$17k liquidity$10 volumecloses 8d

TennisSportsGames

Trade on Polymarket

BUY YES

Cost: 86.0¢
Implied chance: 86.0%
Return if right: 16.3%
Spread cost: 18%

If you put in $100

You get 116.3 shares at 86.0¢ each.

YES wins: $116.28 back, a profit of $16.28. YES loses: $0.00, and the whole $100 is gone.

The gap between buyers and sellers takes $3.48 of that profit. Without it you would make $19.76.

Assumes the whole order fills at this price. A large order eats into the book and averages worse.

Buy YES on Polymarket

BUY NO

Cost: 19.0¢
Implied chance: 19.0%
Return if right: 426.3%
Spread cost: 16%

If you put in $100

You get 526.3 shares at 19.0¢ each.

NO wins: $526.32 back, a profit of $426.32. NO loses: $0.00, and the whole $100 is gone.

The gap between buyers and sellers takes $79.74 of that profit. Without it you would make $506.06.

Assumes the whole order fills at this price. A large order eats into the book and averages worse.

Buy NO on Polymarket

Chance over time

1H 6H 1D 1W 1M ALL

Latest: Aug 17, 06:28 AM4 further outcomes not shown

Latest news

headlines link to their publishers

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Headlines are matched on the names in “Cincinnati Open: Marta Kostyuk vs Sloane Stephens”. Nobody checks them by hand, so one may not be relevant. They also say nothing about whether the price has already moved on this news.

How this market resolves

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.

Source: https://www.wtatennis.com/scores