National Bank Open: Alexander Zverev vs Tallon Griekspoor

Platform comparison

Market context

Polymarket is pricing this Alexander Zverev–Tallon Griekspoor match at **0% YES**, which on the Polygon-based contract means traders are currently assigning essentially no chance that the market resolves to Zverev advancing. The market settles on the player who advances, paid out in USDC via conditional tokens; if the match is not played, is tied, or is delayed beyond seven days without a winner, it resolves 50-50 instead.

That near-zero price is best read against the pair’s recent history. Griekspoor already beat Zverev in Montreal this week, taking a three-set win at the National Bank Open and earning his third top-five victory, which is the cleanest comparable case for why some traders would lean away from Zverev even though he entered the event as the higher-ranked player.[8] The ATP also lists this as a second-round match in Montreal, and the event pages show Zverev and Griekspoor paired again at the same tournament site, which underlines that the market is tied to the tournament’s actual advancement path rather than a generic head-to-head view.[2][3][17]

For traders, the main catalysts are straightforward: official match scheduling, any change in court assignment or start time, and the live result itself. Current listings show the contest as upcoming on 5 August at Centre Court / Court Central, but tennis schedules can move quickly if earlier matches run long or weather/disruptions intervene.[1][3][4] The practical Polymarket read is that a delayed start still leaves the contract live, while a failure to play at all, or a delay beyond the seven-day window, pushes it to the tie outcome under the market rules.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 Polymarket Alternative 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%.