TOTAL VOLUME:
$54.4b
24H VOL:
$234,875,025
OPEN INTEREST:
$1,205,330,693
501,301
Markets across
13,585
events
MATCHED EVENTS:
1,825
PLATFORM COVERAGE:
4
Polymarket:
51%
VS.
Kalshi:
49%
S&P 500 (SPX) Up or Down on March 24?
Description
This market will resolve to "Up" if the official S&P 500 Index closing price for S&P 500 (SPX) on Tuesday, March 24, 2026 is higher than the official S&P 500 Index closing price for SPX on the most recent prior trading day. This market will resolve to "Down" if the official S&P 500 Index closing price for S&P 500 (SPX) on Tuesday, March 24, 2026 is lower than the official S&P 500 Index closing price for SPX on the most recent prior trading day. E.g., ordinarily, a market on Monday would refer to the previous Friday for its most recent closing price, unless that Friday were a market holiday, in which case it would refer to Thursday, or the next most recent trading day. If the two specified closing prices are exactly equal, this market will resolve 50-50. Note that all figures will be rounded to the nearest cent using standard rounding. If SPX does not trade at all during the regular session, the market will resolve 50-50. If either of the relevant days are shortened (for example, due to a market holiday schedule), the official closing price published by S&P 500 Index for that shortened session will still be used for resolution. If either of the relevant days have no official closing price (for example, due to a trading halt into the market close, system issue, delisting, or other disruption), the market will use the last valid on-exchange trade price of the regular session as the effective closing price. The resolution source for this market is the Wall Street Journal, specifically the Close values published by the WSJ under "Historical Prices". US: https://www.wsj.com/market-data/stocks EMEA: https://www.wsj.com/market-data/stocks/emea ASIA: https://www.wsj.com/market-data/stocks/asia
PredictionHero - Resolution Divergence Alerts (RDA)
Divergence Detected
Issue:
Polymarket and Kalshi use fundamentally incompatible resolution frameworks. Polymarket resolves based on directional price movement (Up/Down vs. prior trading day), while Kalshi contains 60 duplicate absolute price-level thresholds (all resolving YES if SPX closes above various levels) with no NO resolution condition specified, making Kalshi's market logically incomplete and unresolvable.Hero Tip:
Do not trade Kalshi's version of this market. Kalshi's rules list only YES resolution conditions across 60 identical threshold statements with no corresponding NO clause, creating a logical void. Polymarket's market is resolvable: it compares March 24 close to the prior trading day close. If you hold Kalshi contracts, expect settlement delays or platform discretion to fill the gap.Critical Divergence Points:
- Polymarket: Distinct stance: Polymarket resolves based on directional comparison—YES (Up) if March 24, 2026 SPX close is higher than the most recent prior trading day close; NO (Down) if lower; 50-50 if equal. Source is Wall Street Journal Historical Prices. 'This market will resolve to Up if the official S&P 500 Index closing price for S&P 500 (SPX) on Tuesday, March 24, 2026 is higher than the official S&P 500 Index closing price for SPX on the most recent prior trading day.'
- Kalshi: Distinct stance: Kalshi lists 60 identical conditional statements, each resolving YES if end-of-day SPX on March 24, 2026 exceeds a specific absolute price level (ranging from 5749.9999 to 7224.9999). No NO resolution condition, NO tie-breaker, and no prior-day comparison logic is provided. 'If the end-of-day S&P 500 index value on March 24, 2026 is above 5849.9999, then the market resolves to Yes.' (repeated 60 times with different thresholds, no complementary NO clause).
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