Roland Garros WTA: Marta Kostyuk vs Iga Swiatek

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Market context

Marta Kostyuk faces Iga Swiatek in the Roland Garros women's draw, with the Ukrainian ranked 19th and the Polish world number two among the tournament favourites. The 30% implied probability for Kostyuk reflects the substantial gap in seeding and recent form, though the clay-court surface at Roland Garros historically favours Swiatek's baseline dominance and topspin game. Kostyuk has shown resilience on slower courts but enters this fixture without a title on clay since 2023, whilst Swiatek claimed the Rome Masters in May 2026 and has won Roland Garros twice previously.

Head-to-head records between these players show Swiatek leading 3–1, with her most recent victory coming on clay at Madrid in 2024. Kostyuk's sole win came on hard court, suggesting the surface disparity is material. When lower-ranked challengers have upset Swiatek at Roland Garros, it has typically required either a significant dip in her form or an opponent with exceptional serving and court coverage—attributes Kostyuk possesses but has not yet synthesised consistently at this level.

Traders should monitor Swiatek's fitness status in the days preceding the match; she carried a minor shoulder concern through the Rome event. Kostyuk's draw positioning and any late-stage coaching adjustments will also matter. The 5:00 AM ET scheduling may favour neither player particularly, though early-round matches at Roland Garros occasionally produce upsets when top seeds are undercooked. Settlement hinges on match completion by 7 June, with weather delays common during the Paris fortnight.

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 Sport Prediction, which mirrors the Polymarket order book directly.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

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FAQ

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On Sport Prediction, 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.

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Not under $1,500 of lifetime trading volume. Above that threshold, Sport Prediction triggers a quick verification flow that finishes in minutes.

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.