National Bank Open: Mariano Navone vs Arthur Fils

Platform comparison

Market context

Polymarket has this contract trading at **4% YES**, which is far below the match-level pricing implied by most tennis books and model sites, where Arthur Fils is generally treated as the clear favourite and Navone as a live outsider.[2][5][6] On Polymarket, the outcome settles through the on-chain conditional-token structure on **Polygon** and is ultimately paid in **USDC**, so the market is not about the scoreline or set handicap; it is simply whether Navone advances against Fils before the settlement window closes.[9]

That 4% tag is best read as a blended view of win probability and event-risk, because prediction markets can price not only the favourite’s edge but also the chance of a walkover, retirement, cancellation or delay that pushes the market into its fallback resolution.[9] Comparable pre-match pricing around this fixture has typically sat much higher for Fils than Navone, with several independent projections putting Fils around the high-60s to low-70s and Navone near the low-30s, while sportsbooks have also lined up on the French player as the stronger side.[1][2][3][6][7]

For traders, the key catalysts are the official ATP scheduling, any late order-of-play changes, and any update on player fitness or withdrawal status before first serve, because those are the events most likely to move a contract that can still resolve 50-50 if the match is not completed in the required window.[9] The market description sets an original start time of 6 August 2026 at 12:30pm ET, but the practical watchpoints are whether the match actually begins, whether either player retires, and whether tournament officials publish a revised schedule after weather or court-delivery disruption.[9]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track National Bank Open: Mariano Navone vs Arthur Fils across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

UK Frequently Asked Questions

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 Kalshi UK. 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.