S&P 500 (SPX) Up or Down on August 3?

Platform comparison

Market context

The S&P 500 is trying to extend a rebound after finishing Friday up 0.7% at 7,489.72, with the move driven by stronger-than-expected earnings from large technology names and a firmer risk tone into the new week.[2][13] With the contract currently pricing **100% YES**, the market is implying almost no chance of a down close versus the prior session, which is materially firmer than a simple directional call and leaves little room for a negative surprise in today’s cash session.[2][13]

That optimism needs to be read against a more mixed summer backdrop. The index had just come through a volatile week, and several market strategists noted that the recent recovery has repaired the tape more than the underlying breadth, with participation still narrow and August seasonality typically less favourable for equities.[5][9][16] Comparable episodes show that the S&P 500 can continue higher after a strong Friday close, but when the move rests on a handful of megacap names, same-day follow-through often depends on whether breadth improves rather than on headline index strength alone.[2][9][10]

For Monday’s catalyst list, traders are watching a dense morning macro calendar: the final July S&P Global manufacturing PMI at 9:45 a.m. ET, followed by construction spending and the ISM manufacturing survey at 10:00 a.m. ET, all of which can shift Treasury yields and equity futures intraday.[1][10] The market is also sensitive to overnight geopolitical headlines and any move in oil, while futures were already described as firmer into the open after weekend easing in Iran-related risk rhetoric.[4][13] On the earnings side, Palantir and other reports on the docket may affect sentiment in the same large-cap growth cohort that has recently been carrying the index.[1]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews S&P 500 (SPX) Up or Down on August 3? 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 Best Prediction Markets UK, 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.

FAQ

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 Best Prediction Markets UK. 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.

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.

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.