National Bank Open: Fabian Marozsan vs Matteo Arnaldi

Platform comparison

Market context

Fabian Marozsan and Matteo Arnaldi are still awaiting their National Bank Open second-round match, and the live market is pricing Marozsan as a modest favourite at 56% despite Arnaldi being the higher-ranked player on ATP listings. Scheduled feeds for the tie place it on Court 2 in Montréal, with listing pages showing the match on 5 August and no completed result yet, so the immediate driver is simply whether the fixture starts and finishes as planned.[1][5][17]

That pricing sits close to a split decision rather than a strong conviction. Historical and odds-based previews have gone both ways: some pre-match models and tipsters have leaned Arnaldi, while others have had Marozsan marginally ahead, and one current odds snapshot gives Marozsan about 57.5% implied probability versus 43.0% for Arnaldi.[2][3][7][8] In that sense, 56% YES reads as a fairly standard one-touch favourite line for a volatile ATP Masters-level matchup rather than a market expecting a clear mismatch.[1][7]

The main catalysts are logistical rather than strategic: final court scheduling, any delay in the Montréal order of play, and whether the match is moved because of weather or backlogs. Tennis listings and live-score pages are the best near-term indicators to watch, because a late start, suspension, or cancellation could push the market towards a 50-50 settlement under the event rules if no winner is decided within the required window.[1][9][13][17]

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 Prediction Today, which mirrors the Polymarket order book directly.

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

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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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%.