Pronóstico: S&P 500 (SPX) Opens Up or Down on July 22?

Platform comparison

Market context

Polymarket is pricing this contract at **100% Down** and **0% Up** on the current screen, so the market is effectively saying the July 22 SPX cash open should print below the prior regular-session close. The contract settles on the official S&P 500 index open versus the most recent prior trading day’s close, so the key for Polymarket users is the opening auction level on the cash index, not the futures tape or where the index trades intraday.[3]

That pricing sits against a backdrop where the S&P 500 just closed higher on Tuesday, rising 0.9% to 7,509.20 after a tech-led session that also saw semiconductor strength offset some tariff and geopolitical noise.[1] For a prediction market reader, that matters because the contract is a binary gap bet: the move from yesterday’s close into today’s open is what counts, and the on-chain position is held in USDC on Polygon through conditional tokens, so the P&L is tied to the exact settlement definition rather than a broad directional view of equities.

For catalysts, traders should watch pre-open headlines that can shift the opening print, especially tariff announcements, Middle East developments, and any overnight move in rate expectations or megacap tech. A fresh market note said tariff headlines were again in focus and that the dollar had strengthened broadly against G10 currencies, which can feed into risk sentiment before the cash open.[2] In practice, SPX opening direction will also be shaped by futures positioning, any late corporate guidance, and whether the opening imbalance favours buyers or sellers in the first auction.

Sources: 1 · 2 · 3

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Qué Es, which mirrors the Polymarket order book directly.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 Polymarket Qué Es. 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.

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.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.