US Open, Qualification WTA: Tamara Zidansek vs Guiomar Maristany

Platform comparison

Market context

Polymarket is pricing Tamara Zidansek vs Guiomar Maristany as effectively locked at 100% YES, which in practice means the contract has already been tied to the on-chain outcome rather than to a live pre-match coin toss. On Polymarket, this sort of tennis market settles through conditional tokens in USDC on Polygon, so the relevant question is whether the recorded match result clears the event criteria before the settlement deadline, not which player looked stronger on paper.

That 100% price usually reflects a completed result or an outcome that the market has treated as certain enough to remove meaningful two-sided trading. In comparable Grand Slam qualifying markets, prices often snap to the winner once a match is finished, then stay pinned unless there is a cancellation, retirement without a winner, or a data error that pushes the contract towards the fallback 50-50 settlement. Zidansek and Maristany were both in the US Open qualifying draw, where one player needs to advance through the round to resolve the market, so the current pricing should be read as a statement about recorded advancement rather than pre-match expectation. Tennis market pages also showed the contest as completed on Court 16, with Zidansek listed as the winner.

The main things a trader would still watch are official draw feeds, late score corrections, and any tournament-side change to the status of the match, because those are what can affect whether the contract resolves cleanly or falls into the no-winner clause. The US Open qualifying schedule ran in Fan Week before the main draw began on 31 August, so this match sat inside the narrow window where administrative updates, walkovers, or amended results matter more than broader tournament context.

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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 Polymarket Scam?, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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.

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%.