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

Platform comparison

Market context

The S&P 500 is coming off a record close, which is the main reason this market is leaning **Up** rather than **Down**. On Tuesday, the index rose 1.8% to 7,736.52, a new all-time closing high, after oil prices eased and large-cap earnings, especially in AI-linked names, helped investors look past recent volatility.[1][11] Reuters said the benchmark had just posted its first record close in two months, underscoring how quickly sentiment has turned back towards a risk-on footing.[7]

For context, a 71% YES price implies traders think the recent breakout has more follow-through than not, but not enough to rule out a sharp reversal. That is consistent with a market that has been advancing from a relatively narrow leadership base: several reports this week pointed to AI megacaps and falling energy prices as the immediate drivers, while technical analysts noted the index was only just clearing a key prior resistance area around 7,620.[8][14] In other words, the current probability is less about a broad, stable trend and more about whether the latest record close survives another session of profit-taking.

The main catalyst to watch is today’s macro calendar and any fresh guidance from the corporate side. Saxo noted that Wednesday’s schedule includes the ISM Services PMI and ADP employment report, while no major central-bank decision is due.[8] Reuters also highlighted that investors are still digesting earnings season and geopolitical developments, so any surprise in labour data, rates expectations, or Middle East headlines could quickly shift the close away from the current bullish lean.[7]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page tracks S&P 500 (SPX) Up or Down on August 5? across four political prediction venues. Live odds come from the Polymarket order book (the deepest political prediction-market book). Kalshi is the CFTC-regulated US alternative, Betfair the established UK sports-exchange with politics markets, Manifold the open play-money variant. For users geo-blocked from Polymarket directly, brokers like Trump Prediction provide a 0%-fee route into the same order book.

Resolution & payout

Political markets typically settle on official candidate or agency confirmation. Polymarket uses UMA Optimistic Oracle: a proposer posts the outcome with a bond, the two-hour window opens, then the smart contract pays USDC.

Kalshi settles USD via CFTC clearinghouse, with clearly defined resolution sources (e.g. AP race calls for elections). Betfair settles after the official outcome is registered with the league or agency. Manifold is play-money.

UK Frequently Asked Questions

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

Can prediction markets influence election outcomes?

Markets reflect expectations rather than create them. Studies show public-facing markets can anchor expectations, but don't influence the underlying outcome. Political markets are information, not advocacy.

Which platform has the deepest political liquidity?

Polymarket — by far. US 2024 presidential volume was ~$3.5B vs Kalshi (~$200M) and Betfair (~$120M). Where Polymarket is geo-blocked, brokers like Trump Prediction route into the same order book at 0% fees.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

Are UK election prediction markets available from the UK?

Yes. Betfair Exchange and Smarkets offer UKGC-regulated UK election markets (seat counts, party share, constituency results). Polymarket also lists UK election contracts with deeper global liquidity. Betfair winnings are typically tax-free for UK individuals; Polymarket profits are subject to HMRC CGT.