Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Kalshi UK Pick polygram.ink |
30% | 70% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Open on Kalshi UK → |
Polymarket polymarket.com |
30% | 70% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | Open on Kalshi UK → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | Open on Kalshi UK → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | Open on Kalshi UK → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | Open on Kalshi UK → |
Live odds for Polymarket-based markets come from the Polygon order book. Non-Polymarket venues show attributes only; clicking any row opens the market on Kalshi UK.
Active sub-markets
| Roland Garros WTA: Marta Kostyuk vs Iga Swiatek | 30% YES | 71% NO |
| Completed Match | 76% YES | 24% NO |
| Roland Garros WTA: Marta Kostyuk vs Iga Swiatek Set 1 O/U 8.5 | 67% YES | 33% NO |
| Roland Garros WTA: Marta Kostyuk vs Iga Swiatek Match O/U 21.5 | 47% YES | 54% NO |
| Roland Garros WTA: Marta Kostyuk vs Iga Swiatek Set 1 Winner | 34% YES | 67% NO |
| Roland Garros WTA: Marta Kostyuk vs Iga Swiatek Total Sets: O/U 2.5 | 37% YES | 63% NO |
Market context
Market consensus: 30% chance of roland garros wta: marta kostyuk vs iga swiatek. Prediction markets aggregate real capital to produce this probability signal. This market refers to the tennis match between Marta Kostyuk and Iga Swiatek in the Roland Garros WTA, originally scheduled for May 31, 2026 at 5:00AM ET. This market will resolve…
Methodology
We track Roland Garros WTA: Marta Kostyuk vs Iga Swiatek on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.
Resolution & payout
Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.
Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.
FAQ
- Where can I trade this market with the lowest fees?
- On Kalshi UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.
- Is this market available outside the US?
- Kalshi UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.
- How does resolution work?
- Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.
- What's the difference between YES and NO shares?
- A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.
- How reliable are the quoted odds?
- The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.
Trade Roland Garros WTA: Marta Kostyuk vs Iga Swiatek on Kalshi UK
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