Wimbledon WTA: Irina-Camelia Begu vs Katie Swan

Platform comparison

Market context

The upcoming Wimbledon WTA first-round clash between Irina-Camelia Begu and Katie Swan, originally slated for 29 June 2026, now carries a crowd-implied probability of 0% for Begu advancing, a stark divergence from initial odds that favoured her slightly. This contract, trading on Polymarket via USDC on the Polygon network, resolves to Begu if she wins, to Swan if she prevails, and to a 50-50 fair price if the match is cancelled before a ball is played or delayed beyond seven days without a winner.

Historically, such extreme probability shifts in tennis markets often signal a pre-match withdrawal or injury rather than a genuine performance deficit, as seen when conditional tokens on similar platforms like Kalshi resolved to fair prices after players forfeited before play commenced [3]. Begu and Swan have met twice previously, with Swan holding a 1-0 head-to-head advantage, including a 1-0 record on grass, yet initial odds still favoured Begu at 1.86 against Swan’s 1.94, suggesting the market now reacts to new information rather than pure form [1][10].

Traders should monitor official WTA announcements for any withdrawal notices or schedule changes, as the match’s resolution hinges on whether a ball is played to trigger the conditional token outcome [3]. Recent head-to-head analysis from Tennis Tonic still projects Begu to win in three sets, making the 0% market price highly anomalous and dependent on external catalysts like injury updates or administrative cancellations [1]. The settlement window closes on 6 July 2026, so any delay beyond two weeks will keep the market open until the rescheduled match concludes.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Scam?. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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 Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.