Lexus Eastbourne Open: Petra Marcinko vs Madison Keys

Platform comparison

Active sub-markets

Market context

The underlying real-world event is the WTA Eastbourne Open semi-final tennis match between Petra Marčinko and Madison Keys, originally scheduled for 7:30 AM ET on 26 June 2026 at Centre Court, Eastbourne. Historical precedents in WTA tournaments show that when a match begins and one player retires due to injury, the outcome resolves definitively to the advancing player, with the prediction market settling at 50-50 only if the match never starts or ends in a tie. In this specific case, Keys advanced after Marčinko retired due to an abdominal injury at 6-1, 0-0, confirming a decisive result rather than a fair price[1][2][5].

Traders should monitor official WTA communications regarding player fitness for the upcoming final against Tatjana Maria, as any further injury updates could influence Keys’ performance odds in subsequent markets[2]. The settlement window closes on 3 July 2026, and while the semi-final result is already confirmed, the prediction market’s 50% YES implied probability diverges meaningfully from sportsbook lines that heavily favour Keys, reflecting a mispricing between analyst consensus and crowd sentiment[3]. Recent coverage on the Tennis Channel confirms Keys’ progression to the final, underscoring the factual resolution of the contract[4].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Lexus Eastbourne Open: Petra Marcinko vs Madison Keys 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 PolyGram — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

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 PolyGram, 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.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram 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.