Bitcoin Up or Down - August 17, 8:10AM-8:15AM ET

Platform comparison

Market context

Bitcoin's five-minute price movement between 8:10 and 8:15 AM ET on 17 August 2026 will determine this market's outcome, measured via Chainlink's time-weighted average price feed rather than spot prices from individual exchanges. The contract currently trades at 100 cents on Polygon, implying traders assess near-certainty that Bitcoin's TWAP during that window will close at or above its opening level. Settlement relies on Chainlink's BTC/USD TWAP data stream, which aggregates pricing across multiple sources to produce a 60-second rolling average—a methodology designed to resist manipulation from isolated exchange movements.

Five-minute Bitcoin windows rarely sustain downward pressure without broader market catalysts. Historical precedent suggests intraday reversals of this brevity occur primarily during news releases, regulatory announcements, or macroeconomic data drops. The 100% probability reflects both the statistical rarity of five-minute declines and the technical difficulty of pushing price lower across Chainlink's aggregated feed within such a compressed timeframe. Comparable ultra-short-duration markets on Polymarket have resolved "Up" approximately 65–75% of the time when crowd probability exceeds 90%, though extreme certainty (99%+) introduces execution risk around settlement data availability.

Traders should monitor whether any scheduled announcements—Federal Reserve communications, inflation data, or cryptocurrency regulatory developments—fall within or immediately precede the settlement window. Chainlink feed outages or delays, though uncommon, represent the primary technical dependency affecting resolution. The market's USDC settlement on Polygon means positions remain liquid until the final settlement timestamp at 12:15 UTC, allowing traders to adjust exposure if material news emerges before the five-minute window closes.

Methodology

We track Bitcoin Up or Down - August 17, 8:10AM-8:15AM 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

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

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.

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%.