Japan Women's Open: Katerina Siniakova vs Peyton Stearns odds, Oct 18: Kalshi vs Polymarket
Katerina Siniakova 55% on Kalshi, 55% on Polymarket. Both exchanges' prices for every outcome of Japan Women's Open: Katerina Siniakova vs Peyton Stearns, Oct 18, $10 traded in 24 hours, updated every 45 seconds.
Sun, Oct 18, 2026, 9:00 PM ET · WTA tennis matches · $10 traded in 24h across both venues
Katerina Siniakova: Kalshi $0.55 vs Polymarket $0.55, +$0.01
Mid prices, in dollars on a contract that pays $1 if it happens: $0.55 is a 55% chance. The gap is Kalshi minus Polymarket.
Two separate exchanges, two accounts. Links may carry a referral code, which never changes what is shown. Disclosures.
All outcomes
| Outcome | Kalshi bid / ask | Polymarket bid / ask | Gap, + = Kalshi higher |
|---|---|---|---|
| Katerina Siniakova | $0.53 / $0.57 | $0.53 / $0.56 | +$0.01 |
| Peyton Stearns | $0.43 / $0.47 | $0.44 / $0.47 | −$0.01 |
Price history, last 3 days
How this is matched
Games are matched across the two exchanges by league, team codes and date. Polymarket prices come from its live order book, Kalshi from its public API. Refreshed every 45 seconds.
What this is not
Read-only. Nothing here places or routes orders and nothing is advice. Fees, slippage and the time it takes to move money between venues are not in these numbers.