Real Sociedad de Fútbol B vs. CD Castellón

Platform comparison

Market context

Real Sociedad B against CD Castellón is priced at 0% YES in the market, which points to the contract effectively treating the match as already beyond the settlement window rather than implying anything useful about the football itself. On Polymarket, the position is held in USDC on Polygon and settles through conditional tokens, so once the event clock closes, the contract resolves off the specified match outcome rather than any live price drift.

For form and comparables, this is the kind of early-season Segunda División fixture where reserve teams can move sharply on limited information, while established sides tend to attract the wider end of the range if there is any uncertainty over squad strength. Head-to-head data is modest but not one-sided, with recent match listings showing a balanced record and this tie opening the campaign at Zubieta, which matters more than it would in a mid-season market because team news and venue information carry disproportionate weight at the start of a run-in or season.

A trader would usually watch for the confirmed kick-off status, the official match report, and any late squad or referee updates, because those are the dependencies that can alter how the contract should be read before expiry. Here, the fixture was scheduled for Friday 14 August 2026 at 18:30 UTC, with coverage placing it at Estadio Zubieta in San Sebastián, so the main catalyst is whether the event actually proceeded on time and in the stated venue before the 18:30Z settlement cut-off.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Real Sociedad de Fútbol B vs. CD Castellón 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

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

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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%.