Bitcoin Up or Down - August 17, 12:00AM-4:00AM ET

Platform comparison

Market context

Bitcoin's price movement over a four-hour window on 17 August will be measured using Chainlink's time-weighted average price feed rather than spot prices from individual exchanges. The market settles to "Up" if the TWAP across 12:00AM to 4:00AM ET remains at or above the opening level; otherwise it resolves "Down". The current 100% YES probability reflects the conditional token pricing on Polygon, where YES tokens trade at parity with USDC, indicating traders see near-certainty in an upward or flat four-hour period.

Chainlink TWAP feeds aggregate data across multiple venues and smooth price discovery over 60-second intervals, reducing the impact of flash movements or single-exchange volatility. Historical precedent suggests overnight windows in August typically see lower volume and tighter ranges; Bitcoin's intraday swings rarely exceed 2–3% during low-liquidity Asian trading hours. The 100% pricing may reflect this seasonal pattern rather than fundamental conviction, as four-hour windows statistically favour modest upside or consolidation over sharp declines.

Traders should monitor Federal Reserve communications and US economic data releases scheduled for 16–17 August, as overnight sentiment often shifts on macro headlines released during US market hours. Bitcoin's correlation with equity futures and Treasury yields remains material; any unexpected inflation data or rate-guidance commentary could trigger volatility before the settlement window opens. Chainlink's feed reliability and any temporary outages would also affect settlement mechanics, though such disruptions remain rare.

Methodology

We track Bitcoin Up or Down - August 17, 12:00AM-4:00AM ET 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

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

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 Polymarket Scam?. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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%.