S&P 500 (SPX) Up or Down on August 5?

Platform comparison

Market context

The immediate change in the last 24 hours is that US equities pushed back into record territory, with the S&P 500 closing sharply higher on Tuesday after a two-day slide in crude oil and improving risk sentiment around the Middle East. Zacks reported the index rose 1.8% to 7,736.52, its first all-time closing high in two months, while CNN said the broad market also made a fresh intraday peak above 7,758 on the same session.[1][8]

That puts the market’s **34% YES** price against a backdrop of strength that is real but not unambiguous. The recent run has been driven by a mix of easing oil prices, resilient earnings, and broadening participation beyond megacap technology, but technical analysts cited by CNBC say the prior June high around 7,620 needed a decisive multi-session break to confirm a cleaner trend change.[17] In that sense, a below-even chance of “Up” implies traders are still discounting the odds that the index can hold record levels into the close rather than merely trade there intraday.[1][17]

For the rest of the session, the main catalysts are the close itself, any late reversal in crude, and whether bond yields continue to pressure rate-sensitive stocks. Reuters-style market coverage was not available in the supplied results, but contemporaneous reports noted a mixed open with tech softer and the S&P 500 only marginally firmer at one point, which matters because this market settles on the official closing level versus the prior trading day, not on the intraday high.[4][5]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews S&P 500 (SPX) Up or Down on August 5? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Prediction Today, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 Prediction Today. 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%.