National Bank Open: Marta Kostyuk vs Madison Keys

Platform comparison

Market context

National Bank Open: Marta Kostyuk vs Madison Keys — current market-implied probability: 57%. This market refers to the tennis match between Marta Kostyuk and Madison Keys in the National Bank Open, originally scheduled for August 5, 2026 at 11:00AM ET. This market will resolve to 'Marta Kost…

Methodology

Football-specific comparison page for National Bank Open: Marta Kostyuk vs Madison Keys. Polymarket's live quote (Polygon order book) plus platform attributes for the three reference venues. Sports markets reward liquidity — Polymarket and Betfair are materially deeper than Kalshi (US-focused) or Manifold (play-money).

Resolution & payout

Sports markets typically settle on official final-whistle plus league confirmation. Polymarket uses UMA Optimistic Oracle with a source URL per contract — usually official league data feeds or ESPN/Soccerway. Two-hour dispute window, then smart-contract payout in USDC.

UK Frequently Asked Questions

When do sports markets resolve?

Typically within hours of the official final whistle. Polymarket uses UMA Optimistic Oracle with source URLs pointing at official league data feeds — e.g. the Premier League for EPL markets, UEFA for Champions League, FIFA for World Cup.

Can I bet on individual matches?

Yes, Polymarket lists every major Premier League / Champions League / World Cup match as its own market. Liquidity varies — top matches like El Clásico or a semi-final often have six-figure pools, lower-league games closer to three-figure.

How fast do sports winnings settle?

Once the official league outcome is logged in the UMA Oracle (typically 1-2 hours after the final whistle), Polymarket's smart contract triggers USDC payout. To your wallet within minutes.

What's the difference between match odds and outright odds?

Match odds cover a single game ("Bayern beats BVB"). Outright odds are long-term aggregates ("Bayern wins the league"). Outright markets have deeper liquidity; match markets have faster resolution.

Can I trade Premier League prediction markets from the UK?

Yes. Polymarket has Premier League outcome markets (title winner, relegation, top scorer). For UK traders wanting GBP settlement and UKGC protection, Betfair Exchange and Smarkets offer Premier League futures and match markets. Betfair is the deepest liquidity venue for UK football exchange markets.