US Open, Qualification WTA: Savannah Broadus vs Tyra Caterina Grant

Platform comparison

Market context

The match was scheduled for the opening days of US Open qualifying in New York, and the market now sits against a real completed result after Tyra Caterina Grant beat Savannah Broadus 6-2, 6-4 in the first round. Broadus entered as the lower-ranked player, with Grant around the top 150 in singles and Broadus just outside the top 300, so the on-court gap was modest but clear enough to make Grant the likelier advance candidate.

That ranking spread matters because qualifying ties like this often resolve in line with seeding, current level and recent hard-court form rather than reputation alone. Broadus was a wild card making her Grand Slam qualifying debut, while Grant brought more established tour-level and junior pedigree into the tie, which is the sort of profile that usually shortens the price on the better-ranked player in early-round qualifying.

For traders, the key watchpoint is no longer the match itself but whether the result is fully official within the settlement window, since the market rules flip to 50-50 only if no winner is determined by 7 September. The US Open qualifying schedule ran from 24 to 27 August, with the main draws beginning on 30 August, so there is little fixture risk left unless the published result is altered by a rare administrative issue or post-match correction.

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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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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%.