S&P 500 (SPX) Up or Down on July 13?

Platform comparison

Market context

The market asks whether the S&P 500 closes higher on Monday, 13 July 2026, than it did on the preceding trading day, Friday 10 July. With the index sitting at 7,575.39 after a 0.42% gain on Friday, the crowd-implied probability of an “Up” close is just 8%, suggesting traders expect a pullback despite the recent momentum [2][4].

Historically, Monday reversals following mid-week gains are not uncommon in the current cycle, where the index has traded within a tight 52-week range of 6,201.59 to 7,620.90, often testing the upper bound before retreating [2][3]. The 8% YES price implies the market views Friday’s close as a local peak, yet this underdog stance may overlook the index’s 20.6% year-on-year rise, which has sustained resilience even near record highs [2]. Contrarian value could sit in the YES leg if volatility remains suppressed and no negative catalysts emerge.

Traders should monitor the 13 July US trading session for any pre-market commentary from Federal Reserve officials or unexpected economic data releases, as these often drive intraday swings near key technical levels [1]. While no specific announcement is scheduled for Monday afternoon, the proximity to the 7,620.90 52-week high means any breach could trigger algorithmic buying, potentially flipping the day’s direction [2][6]. The settlement window closes at 20:00 UTC, so late European session flows may also influence the final print.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track S&P 500 (SPX) Up or Down on July 13? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 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.