Cincinnati Open: Fabian Marozsan vs Michael Zheng

Platform comparison

Market context

Polymarket has this contract at 0% YES, so the on-chain price is effectively saying Fabian Marozsan’s advance is being treated as a dead outcome for now, with value resting in the NO side on Polygon via USDC-settled conditional tokens. The match was originally listed for 14 August at 3:30pm ET, but live tennis listings showed it as a Round 1 Cincinnati Open meeting between Marozsan and qualifier Michael Zheng, which is the event the market is tracking.[14][13]

That 0% print is best read against how tennis contracts behave when the underlying fixture has already started, been delayed, or is no longer expected to be completed inside the settlement window. In this case, the market rules matter as much as the scoreline: if the match is not played, ends level, or slips beyond seven days without a winner, resolution moves to 50-50; if it begins and one player advances, that determines the outcome. Comparable tennis markets often sit near zero once a named player is effectively out, then reprice only if an official restart, completion, or walkover path re-opens.

For traders, the practical catalysts are the tournament’s order-of-play updates, any ATP or event announcement on postponement or court assignment, and whether Cincinnati’s schedule compresses later rounds into the settlement window ending 21 August at 19:30 UTC. The draw sheet placed Marozsan and Zheng in the men’s singles field, and the published schedule has round one running 13–15 August, so any late abandonment, weather delay, or administrative rescheduling is the key dependency rather than broader form talk.[13][11]

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

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

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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%.