Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via Prediction Today) Pick polygram.ink (preferred broker) |
100% | 0% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Live odds → |
Polymarket (direct) polymarket.com |
100% | 0% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | Live odds → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | Live odds → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | Live odds → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | Live odds → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| Completed Match | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Match O/U 21.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Match O/U 22.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Match O/U 23.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set 2 O/U 8.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set 2 O/U 9.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set 1 O/U 10.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set 1 O/U 8.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set 1 O/U 9.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set 1 Winner | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys Total Sets: O/U 2.5 | 100% |
| Wimbledon WTA: Kayla Day vs Madison Keys | 0% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set 2 Winner | 0% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set 2 O/U 10.5 | 0% |
| Wimbledon WTA: Kayla Day vs Madison Keys Set Handicap +/-1.5 | 0% |
Market context
Kayla Day faces Madison Keys in the first round of Wimbledon WTA on Court 18 today, with oddsmakers heavily favouring Keys at -1540 moneyline while Day sits at +770, reflecting a stark 0% crowd-implied probability for Day advancing. The real-world shift in the last 24 hours is Day’s confirmed entry into the main draw after surviving two qualifying rounds, yet her lack of Grand Slam experience remains the dominant narrative cited by analysts as a critical weakness against Keys’ power on grass[2].
Historically, similar matchups between a Grand Slam novice and a seasoned power hitter on Wimbledon grass have produced straight-set losses for the underdog, with Day’s career H2H record against Keys showing an even 1-1 split but no indication of overcoming Keys’ set-winning dominance in recent encounters[3][5]. Past cases where a player with zero major titles faced a top-20 American on grass saw the novice win less than 10% of matches, framing the current 0% probability as consistent with established patterns rather than an outlier[2].
Traders should monitor the official WTA start-time announcement for Court 18, as any delay beyond 10:00 UTC could signal weather disruption or injury, and watch for Keys’ pre-match press comments regarding her fitness after recent training reports[7][10]. A key dependency is whether Day’s qualifying fatigue manifests in the first set, given Keys’ -300 odds for straight-set victory, and any sudden withdrawal news from either player before the match begins would reset the market to 50-50[2].
Methodology
This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Prediction Today, which mirrors the Polymarket order book directly.
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 Prediction Today. 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'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.
- 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.
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