National Bank Open: Fabian Marozsan vs Matteo Arnaldi

Platform comparison

Market context

Polymarket is pricing **Fabian Marozsan** at 56% in USDC-settled conditional tokens on Polygon, so the market is treating him as a slight favourite over Matteo Arnaldi for the National Bank Open meeting. Because the contract resolves on who advances, not on set score, the key for holders is simply whether Marozsan wins outright before the settlement window closes; if the match is not played, or drifts beyond the no-result rules, the contract flips to 50-50.

The historical read is mixed but leans towards Arnaldi on direct evidence. TennisTemple and other match databases show Arnaldi leads the head-to-head 2-0, with both wins coming on clay and no prior hard-court meeting, while the current tournament is on outdoor hard courts in Montréal[1][2][4]. That means the previous results are relevant but not decisive, because surface change can materially alter match-up dynamics. Ranking context also points to a close contest: Tennis.com lists Arnaldi around ATP No. 35 and Marozsan around No. 61, which is consistent with a market that does not price a strong favourite[3].

For traders, the main catalysts are match-day scheduling, any late court or weather changes, and whether the tie stays on the published order of play. Current listings place the match on Court 2 at around 19:30–20:00 UTC, but ATP events can slide if earlier matches run long or if conditions change[1][5][7]. In practice, that matters because Polymarket’s resolution depends on the actual winner or on a no-contest outcome under the contract terms, so withdrawals, walkovers, and delays are the events most likely to move the price around the 56% level[3].

Sources: 1 · 2 · 3 · 4 · 5

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 Kalshi UK, which mirrors the Polymarket order book directly.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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.

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%.