Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via Kalshi Alternative UK) Pick polygram.ink (preferred broker) |
87% | 13% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Trade this market → |
Polymarket (direct) polymarket.com |
87% | 13% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | Trade this market → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | Trade this market → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | Trade this market → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | Trade this market → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| US Open ATP: Ben Shelton vs Tallon Griekspoor | 87% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 2 Winner | 77% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 1 Winner | 75% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 3 Winner | 75% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set Handicap +/-1.5 | 73% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 1 O/U 8.5 | 70% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Total Sets: O/U 3.5 | 51% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Match O/U 36.5 | 51% |
| Completed Match | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 2 O/U 8.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Game Spread +/-5.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 1 O/U 9.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 2 O/U 9.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 4 Winner | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 2 O/U 10.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Match O/U 40.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 3 O/U 8.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 3 O/U 9.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 3 O/U 10.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 4 O/U 8.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 4 O/U 9.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 4 O/U 10.5 | 50% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set Handicap +/-2.5 | 47% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Match O/U 38.5 | 46% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Set 1 O/U 10.5 | 44% |
| US Open ATP: Ben Shelton vs Tallon Griekspoor Total Sets: O/U 4.5 | 19% |
Market context
Market consensus: 87% chance of us open atp: ben shelton vs tallon griekspoor. Prediction markets aggregate real capital to produce this probability signal. This market refers to the tennis match between Ben Shelton and Tallon Griekspoor in the US Open ATP, originally scheduled for August 30, 2026 at 11:00AM ET. This market will resol…
Methodology
We read US Open ATP: Ben Shelton vs Tallon Griekspoor 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
Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.
UK Frequently Asked Questions
- 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.
- Is Betfair a Polymarket alternative?
- Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.
- 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.
- Polymarket vs Betfair Exchange: which is better for UK prediction trading?
- Betfair Exchange offers UKGC regulation, GBP settlement, and potentially tax-free winnings — but focuses on sports and politics only. Polymarket has deeper liquidity, 0% platform fee, global event coverage, and crypto/geopolitical markets Betfair doesn't offer. For UK traders: Betfair for regulated GBP sports markets; Polymarket for broader, global prediction events.
- Is Kalshi available in the UK?
- Kalshi is a US CFTC-regulated prediction exchange. UK residents can create accounts but must use USD and US payment methods. Kalshi's product range overlaps with Polymarket but with lower liquidity on most contracts. For UK traders, Polymarket typically offers better prices due to higher global volume.
Trade US Open ATP: Ben Shelton vs Tallon Griekspoor on Kalshi Alternative UK
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