Retrieve the latest Polymarket order book for "SPX Opens Up or Down on March 18", compare the implied odds against real-time S&P 500 Futures (ES) movement, and update the assessment of fair value and the risk of a flat open (50-50 resolution).

AI-powered analysis for: Retrieve the latest Polymarket order book for "SPX Opens Up or Down on March 18", compare the implied odds against real-time S&P 500 Futures (ES) movement, and update the assessment of fair value and the risk of a flat open (50-50 resolution).. Get detailed insights and real-time data on PolyPredict AI.

Search the economic calendar for March 18 to identify high-impact pre-market releases (e.g., Housing Starts, Jobless Claims) or major earnings scheduled before 9:30 AM ET that could trigger a directional flip in the S&P 500 opening price.

AI-powered analysis for: Search the economic calendar for March 18 to identify high-impact pre-market releases (e.g., Housing Starts, Jobless Claims) or major earnings scheduled before 9:30 AM ET that could trigger a directional flip in the S&P 500 opening price.. Get detailed insights and real-time data on PolyPredict AI.

Analyze the overnight performance of S&P 500 E-mini Futures (ES) and Asian/European markets to determine if current pre-market momentum is strong enough to sustain a clear "Gap Up" or "Gap Down" relative to the previous trading day's close.

AI-powered analysis for: Analyze the overnight performance of S&P 500 E-mini Futures (ES) and Asian/European markets to determine if current pre-market momentum is strong enough to sustain a clear "Gap Up" or "Gap Down" relative to the previous trading day's close.. Get detailed insights and real-time data on PolyPredict AI.

Indicies|$166.7k Vol|

2 hrs 7 mins

S&P 500 (SPX) Opens Up or Down on March 18? - AI Odds Analysis

All Outcomes

Market Price

AI Fair Value

Value Edge

UpDown

0.05¢

99.95¢

99¢

1¢

+99¢

0¢

AI Insights:

3 hours ago Updated

Fair Value Reasoning:

Current time is 10:19 AM ET on March 18, and the US market officially opened at 9:30 AM. Authoritative data establishes the S&P 500 closing price for March 17 at 6,716.09. Real-time news and market data confirm that S&P 500 futures rose ~0.5% pre-market, driven by positive AI sector news (Nvidia, Micron) and easing oil prices, and the spot market explicitly 'opened higher' (trading around 6755). Since the 'open price' resolution event has already occurred and is irreversible, the 'Up' option is the de facto winner, with a fair value of 99-100 cents (leaving 1 cent for settlement confirmation buffer).

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Movers

March 18, 2026, The fair value of 'Up' surged from ~85c pre-market to 99c (near max value) because the US stock market officially opened at 9:30 AM with a price higher than the previous close, effectively resolving the event. March 17, 2026 - March 18, 2026, 'Up' rose from ~58c to ~85c, driven by a sharp rebound in overnight futures. News of Iraq resuming oil exports via Turkey eased fears of supply disruptions, causing oil prices to retreat, while bullish updates from Nvidia and Micron boosted tech sector sentiment, reversing the previous day's panic.

S&P 500 (SPX) Opens Up or Down on March 18? - AI Odds Analysis

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