Roland Garros WTA: Marta Kostyuk vs Iga Swiatek

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Active sub-markets

Market context

Polymarket currently prices Kostyuk's chances at 27% (USDC on Polygon), implying Swiatek as the clear favourite in this Roland Garros matchup scheduled for 31 May 2026. The conditional token structure means traders holding YES shares receive full payout only if Kostyuk advances; NO holders profit if Swiatek progresses. Settlement occurs by 7 June, with a 50-50 resolution triggered if the match doesn't complete within that window—a meaningful tail risk given clay-court weather delays at Roland Garros.

Swiatek's dominance on clay justifies the market's confidence. She has won Roland Garros twice (2022, 2023) and holds a 5-1 head-to-head record against Kostyuk across all surfaces. Kostyuk, ranked around 20th, has improved considerably but lacks the clay-court pedigree and consistency Swiatek demonstrates on the surface. Historical precedent suggests top-seeded clay specialists rarely lose to unseeded opponents in early rounds unless injury or form collapse intervenes. The 27% probability reflects genuine uncertainty rather than a mispricing—Kostyuk's recent trajectory and occasional upset capability keep the market from pricing her below 20%.

Traders should monitor Kostyuk's clay-court preparation tournaments in May and any injury reports from either player in the fortnight before Roland Garros. Swiatek's form entering the tournament matters; she occasionally underperforms in early rounds despite being favourite. Weather forecasts for 31 May could influence match conditions and favour either player's style. The settlement window's seven-day buffer is standard but worth noting given Paris's unpredictable spring weather patterns.

Methodology

This page is a comparison snapshot: one live quote (Polymarket), four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket UK, which mirrors the Polymarket order book directly.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket 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?

Polymarket 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 does it cost to trade on Polymarket UK?

Zero. Polymarket UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.