National Bank Open: Aryna Sabalenka vs Shuai Zhang

Platform comparison

Market context

Polymarket’s contract is pricing **Aryna Sabalenka** at about **94%** on USDC-settled, Polygon-based conditional tokens, so the market is treating this as a heavily one-sided match rather than a coin flip. In practical terms, buyers are paying for a Sabalenka advance, while the main non-result risk sits in the market rules: a cancellation, no-contest, or a delay beyond seven days from the scheduled date can still force a **50-50** resolution.

That price sits broadly in line with outside tennis models and sportsbook markets, which also make Sabalenka a strong favourite. Tennis.com’s match page gives Sabalenka a **88% projected winner** chance, while Dimers shows roughly **90%**, and betting screens in the search results show very short Sabalenka moneyline prices alongside long Zhang prices.[3][13][1] For comparison, the market’s 94% implies even more confidence than those baselines, so Polymarket is effectively charging a premium for the favourite.

For traders, the key catalysts are straightforward: official tournament scheduling, any walkover or injury update, and whether the match starts on time or slips beyond the market’s settlement window. The match was listed for Toronto’s third round, with WTA reporting Zhang had advanced to meet Sabalenka, and live match pages indicate the scheduled time around 23:00.[17][9][15] On Polymarket-style contracts, the practical issue is not only who wins, but whether play begins and reaches a formal result within the window; a late cancellation or prolonged postponement can matter as much as the scoreboard.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track National Bank Open: Aryna Sabalenka vs Shuai Zhang 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

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.

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%.