S&P 500 (SPX) Up or Down on August 7?

Platform comparison

Market context

The setup leans to **Up**, with the market pricing about a **96% YES** chance that the S&P 500 finishes higher than the previous trading day’s close. That makes **YES the heavy favourite** and leaves only a small sliver of implied downside; in handicapper terms, the interest is less in whether the index can rise and more in whether the move is large enough to avoid a late reversal. The most recent closes showed the index easing to **7,482.71 on Wednesday from 7,503.85 on Tuesday**, so the market only needs a modest positive finish on the day to cash an “Up” outcome.[8][14]

History and comparable cases argue that such a high probability usually reflects a strong directional bias rather than certainty. The S&P 500 has recently been trading near record territory, with technicians watching whether it can hold above the **7,620** area that marked prior resistance, while another market note said the index had been consolidating after breaking above its moving averages.[18][11] That sort of backdrop supports the favourite, but it also means the value case for a contrarian “Down” is mostly about price sensitivity to a disappointing catalyst rather than a broad trend change.[18][11]

The main driver to watch is the **July nonfarm payrolls report and unemployment rate**, both scheduled before the open on Friday, August 7, alongside hourly earnings and workweek data.[13][16] A weaker-than-expected labour print could hit risk appetite quickly, while a solid report would reinforce the bullish consensus already embedded in the market. Options pricing ahead of the session pointed to a contained one-day move, which suggests traders are expecting a narrower outcome than the broader bullish tone implies.[4]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track S&P 500 (SPX) Up or Down on August 7? 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 Who Will Win. 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%.