US Open, Qualification ATP: Kei Nishikori vs Michael Antonius

Platform comparison

Market context

Kei Nishikori’s qualifying path at the US Open now hinges on a second-round meeting with Michael Antonius after Nishikori beat Sebastian Ofner 6-1, 2-6, 6-2 in round one.[1][2] The market’s 100% implied YES price is consistent with the event having already moved into the live qualification stage, though the settlement still depends on the match being played and a winner being recorded before the deadline.[1][6]

For programmatic use, this is the sort of market that should be modelled as a schedule-and-status dependency rather than a pure skill price. Nishikori entered qualifying by wildcard for what has been described as his farewell US Open, while Antonius also advanced from round one, defeating Henry Searle 6-1, 6-2.[1][5][13] Historical read-through is straightforward: Nishikori has deep major pedigree, including the 2014 US Open final, but the relevant short-term signal here is his confirmed progression into the Antonius match, not legacy ranking or career record.[2][7]

The key catalysts are official draw updates, match timing changes, and any withdrawal or walkover notices from the US Open or ATP feeds.[2][6][8] As of the latest published schedules, the pairing was listed in qualifying round two on 26 August, which means a trader tracking this through scripts or conditional orders would mainly watch for start status, completion, and any rescheduling before the 2 September settlement window closes.[6][8][11]

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 Polymarket Bot UK, which mirrors the Polymarket order book directly.

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.

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%.