Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via Polymarket Alternative) Pick polygram.ink (preferred broker) |
100% | 0% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Open the market → |
Polymarket (direct) polymarket.com |
100% | 0% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | Open the market → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | Open the market → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | Open the market → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | Open the market → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| US Open WTA: Madison Keys vs Alina Korneeva Set 1 Winner | 100% |
| US Open WTA: Madison Keys vs Alina Korneeva Set 1 O/U 8.5 | 100% |
| US Open WTA: Madison Keys vs Alina Korneeva Set 1 O/U 9.5 | 100% |
| US Open WTA: Madison Keys vs Alina Korneeva Set 1 O/U 10.5 | 100% |
| US Open WTA: Madison Keys vs Alina Korneeva Match O/U 21.5 | 99% |
| US Open WTA: Madison Keys vs Alina Korneeva Set 2 O/U 8.5 | 90% |
| US Open WTA: Madison Keys vs Alina Korneeva Set 2 O/U 9.5 | 90% |
| US Open WTA: Madison Keys vs Alina Korneeva | 89% |
| US Open WTA: Madison Keys vs Alina Korneeva Set 2 Winner | 74% |
| US Open WTA: Madison Keys vs Alina Korneeva Match O/U 23.5 | 60% |
| Completed Match | 50% |
| US Open WTA: Madison Keys vs Alina Korneeva Game Spread +/-4.5 | 50% |
| US Open WTA: Madison Keys vs Alina Korneeva Set 2 O/U 10.5 | 50% |
| US Open WTA: Madison Keys vs Alina Korneeva Total Sets: O/U 2.5 | 44% |
| US Open WTA: Madison Keys vs Alina Korneeva Set Handicap +/-1.5 | 41% |
| US Open WTA: Madison Keys vs Alina Korneeva Match O/U 22.5 | 23% |
Market context
Traders on decentralised prediction markets give 100% probability to us open wta: madison keys vs alina korneeva. This market refers to the tennis match between Madison Keys and Alina Korneeva in the US Open WTA, originally scheduled for August 30, 2026 at 11:00AM ET. This market will resolve to 'Madison Keys' i…
Methodology
We read US Open WTA: Madison Keys vs Alina Korneeva from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.
Resolution & payout
Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.
Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.
FAQ
- Polymarket vs Kalshi — which is better?
- Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.
- What does Polymarket cost vs Kalshi?
- Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.
- What about Smarkets as an alternative?
- Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.
- Are all these platforms regulated?
- No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.
- Which platform supports Klarna/SOFORT?
- Directly: none. Polymarket accepts only USDC on Polygon. Polymarket Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.
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