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

Platform comparison

Market context

The market asks whether the S&P 500 index will close higher on Monday, 13 July 2026 than it did on the last prior trading day, which is typically the preceding Friday. In prediction markets, buying a YES share means you profit if the index closes up, while a NO share profits if it closes down; the current crowd-implied probability of an up day is just 8%, suggesting traders expect a decline.

Historically, single-day moves in the S&P 500 are often small, with the index ranging between 6,201 and 7,621 over the past 52 weeks, and recent weekly expected moves hovering near 98 points[2][3]. Days with such low implied upside probability (under 10%) are uncommon but have occurred during periods of heightened volatility or ahead of negative macro surprises, where the market tends to drift lower rather than surge.

Traders should monitor the US economic calendar for any scheduled data releases on Monday, such as inflation or employment figures, which can trigger immediate price reactions. With the index closing at 7,575.39 on Friday, 10 July, any deviation from the expected range of 7,468 to 7,664 could signal a directional shift[2]. Recent market commentary notes that the upper bound of expected movement is around 7,664, meaning a close above that would require a significant 1.5-standard-deviation move, which is statistically less likely[2].

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

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 Prediction Market UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.

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.