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 outside the top 20 and the Polish world number two among the tournament favourites. The crowd-implied probability of 30% for Kostyuk reflects a significant underdog position, though the gap between their current rankings and recent form warrants scrutiny. Swiatek has won Roland Garros twice and holds a commanding head-to-head record against Kostyuk, winning their last three encounters on clay. The Polish player's dominance on the Paris surface—where she has reached finals in four of her last five appearances—underpins the market's heavy favouring of her progression.

Kostyuk's recent trajectory offers a contrarian angle worth monitoring. She reached the Australian Open quarter-finals in January 2026 and has steadily climbed the rankings through consistent performances on hard courts and grass. However, her clay-court record remains unproven at the highest level, and facing Swiatek in the early rounds represents a severe draw. The Ukrainian has never defeated Swiatek on any surface, a statistical hurdle the 30% probability may not fully discount given the specific context of Roland Garros.

Traders should track pre-match fitness updates and any surface-specific preparation news in the week before 31 May. Swiatek's recent tournament schedule and any signs of fatigue could shift value, though her historical clay dominance and head-to-head advantage suggest the consensus pricing reflects genuine underlying strength rather than overconfidence.

Methodology

This page reviews Roland Garros WTA: Marta Kostyuk vs Iga Swiatek across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at Who Will Win — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

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

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On Who Will Win, 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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How fast are USDC deposits?

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Not under $1,500 of lifetime trading volume. Above that threshold, Who Will Win 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.