National Bank Open (Doubles): Jiang/Wu vs Mertens/Shnaider

Platform comparison

Market context

The match between Jiang/Wu and Mertens/Shnaider was still carrying a strong favourite bias in the last 24–48 hours, but the market has now drifted to **0% YES** on the current contract, which points to the event being treated as effectively over for this settlement window rather than a live upset price. Public sportsbook and market screens still had Mertens/Shnaider well ahead before any final resolution, with prices around 1.26–1.30 against roughly 3.4–3.5 for Jiang/Wu, while tennis tracking pages also showed Mertens/Shnaider as the projected winner by a wide margin.[4][7][12][14]

That fits the broader pattern for doubles markets at this level: when a seeded or higher-rated pairing enters as a clear favourite, the market usually snaps back quickly once live scoring or a final result confirms the direction of play. Tennis.com’s event pages and the active prediction boards both pointed to Mertens/Shnaider as the more likely advance, and the live listings around the tournament showed the fixture in the round-of-16 queue rather than as an open-ended futures angle.[3][6][8] In comparable WTA doubles pricing, pre-match favourite status tends to dominate unless the match is incomplete, which matters here because the contract can still settle 50-50 if the match is cancelled, tied, or delayed beyond the seven-day rule.[5][8]

For traders, the key catalyst is not form but administrative closure: the live scoreboard, official tournament draw updates, and any rescheduling notices from the National Bank Open are what determine whether the contract resolves to a winner or to the fallback 50-50 outcome.[3][9][15][19] If the match has already begun, the main dependency is whether play reaches a completed result before the settlement deadline on 15 August; if not, the market’s contractual delay provision becomes the decisive factor.[8][19]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track National Bank Open (Doubles): Jiang/Wu vs Mertens/Shnaider 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

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.

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%.