Pronóstico: S&P 500 (SPX) Opens Up or Down on July 24?

Platform comparison

Market context

The S&P 500 opens on 24 July 2026 either above or below the previous trading day's close. Polymarket currently prices the "Up" outcome at 0%, implying near-certainty that the index will open lower or flat. This extreme skew reflects either a specific overnight catalyst expected before market open or a technical artefact of low liquidity in this niche contract. On Polygon, traders settle positions in USDC conditional tokens, with resolution tied to official S&P 500 Index data from the exchange.

Historical overnight gaps in the S&P 500 occur with measurable frequency but lack directional consistency. Analysis of the past decade shows roughly 45–50% of opens exceed the prior close, with the remainder opening lower or unchanged. Gap-up mornings typically follow positive earnings surprises, geopolitical de-escalation, or strong overnight Asian equity performance, whilst gap-down opens correlate with earnings misses, central bank hawkishness, or credit events. The 0% probability assigned to "Up" suggests either a known negative catalyst scheduled for the evening of 23 July or a liquidity desert where minimal trading has occurred.

Traders monitoring this contract should watch earnings announcements from major S&P 500 constituents on 23 July, Federal Reserve communications, and overnight moves in Asian and European indices. The settlement window closes at 20:00 UTC on 24 July, allowing the full trading session to resolve the outcome. Any significant macroeconomic data release or corporate guidance revision in the hours before US market open could shift the conditional token prices materially, though the current 0% floor suggests the market has already priced in a directional bias.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Qué Es trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.