Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via BTC Prediction) Pick polygram.ink (preferred broker) |
99% | 1% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | Open live market → |
Polymarket (direct) polymarket.com |
99% | 1% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | Open live market → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | Open live market → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | Open live market → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | Open live market → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| 36°C | 99% |
| 37°C | 2% |
| 30°C or below | 0% |
| 31°C | 0% |
| 32°C | 0% |
| 33°C | 0% |
| 34°C | 0% |
| 35°C | 0% |
| 38°C | 0% |
| 39°C | 0% |
| 40°C or higher | 0% |
Market context
Beijing’s airport maximum for 6 August will be set off the highest reading recorded at Beijing Capital International Airport Station, settled in USDC on-chain rather than in fiat, so the key issue is whether the day produces a late-afternoon spike or stays near the seasonal norm. August in Beijing is typically hot, with published monthly guides and forecasts putting average highs around 29–30°C and occasional 35°C+ days still possible early in the month.[5][15][18]
The current 0% YES implies the market is pricing the outcome as effectively outside the active temperature bands, which is hard to reconcile with the available forecasts showing daytime highs around the low-to-mid 30s Celsius and clear or mostly sunny conditions through much of the day.[13][16] Comparable Beijing August profiles usually show a broad spread between ordinary highs and short-lived heat surges, so traders generally read a flat probability as a sign that the contract may be trading on stale information, thin liquidity, or a range mismatch rather than a settled meteorological view.[1][18]
Catalysts to watch are the hourly airport observations, any convective cloud or shower development that could cap the afternoon high, and whether the benchmark station reports a late peak before the settlement window closes at 12:00 UTC. On the crypto side, this is a simple USDC-settled event, so broader BTC and ETH swings mainly matter if they change risk appetite or draw attention to mispriced small-caps; if spot and perpetuals are calm, these weather contracts often move more on local forecast revisions than on macro tape.
Methodology
Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.
Resolution & payout
Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.
Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.
UK Frequently Asked Questions
- What are crypto prediction markets?
- Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.
- Why USDC and not ETH or USDT?
- USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.
- 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%.
Trade Highest temperature in Beijing on August 6? on BTC Prediction
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