TOTAL VOLUME:
$61.9b
24H VOL:
$249,705,498
24H TRANSACTIONS:
600,069,390
OPEN INTEREST:
$1,354,509,605
579,516
Markets across
14,317
events
MATCHED EVENTS:
4,116
PLATFORM COVERAGE:
4
Polymarket:
50%
VS.
Kalshi:
50%
S&P 500 (SPX) Up or Down on March 30? Odds & Prediction Markets
Volume:
$474,758
6,100 or above 100%
6,300 or above 100%
6,325 or above 100%
Closed: Mar 30, 7:00 PM EST
Kalshi
Outcome
Chance %
Price
Liquidity
Volume
24h
7d
Open Interest
Ends in
Result
Trade
Description
This market resolves based on whether the S&P 500 Index closing price on Monday, March 30, 2026 is higher ('Up'), lower ('Down'), or equal ('50-50 split') compared to the most recent prior trading day's close. The resolution uses official closing prices from the Wall Street Journal's Historical Prices data, with fallback provisions for shortened sessions, trading halts, or other disruptions.
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 relative to prior trading day), while Kalshi resolves based on absolute index level thresholds (44 separate price-level conditions). These frameworks cannot produce identical outcomes for the same underlying event.Hero Tip:
If you trade this event, understand that Polymarket and Kalshi will almost certainly resolve to different outcomes. Polymarket cares only about whether March 30 closes higher or lower than March 27 (or the prior trading day). Kalshi cares only about whether the absolute closing value exceeds one of 44 specific thresholds. A market that resolves UP on Polymarket (higher close than prior day) could resolve NO on all 44 Kalshi conditions if the absolute level is below the lowest threshold (5724.9999), and vice versa. Do not assume cross-platform arbitrage opportunities without explicitly calculating both outcomes.Critical Divergence Points:
Polymarket:
Outlier: Resolves based on directional price movement only. Market resolves UP if March 30 closing price is higher than the most recent prior trading day closing price, DOWN if lower, and 50-50 if equal. Source is Wall Street Journal Historical Prices. Logic: 'This market will resolve to Up if the official S&P 500 Index closing price for S&P 500 (SPX) on Monday, March 30, 2026 is higher than the official S&P 500 Index closing price for SPX on the most recent prior trading day.'Kalshi:
Outlier: Resolves based on absolute index level thresholds only. Market contains 44 separate YES/NO conditions, each tied to whether the end-of-day SPX value exceeds a specific price level (ranging from 5724.9999 to 7199.9999). No directional comparison to prior trading day is performed. Logic: 'If the end-of-day S&P 500 index value on March 30, 2026 is above [threshold], then the market resolves to Yes.'
Our PredictionHero Resolution Divergence Alerts (RDA) are there to help users identify potential differences across platforms. They do not replace or supersede the official rules and description of any prediction market. Users are solely responsible for reviewing and understanding the applicable rules and resolution criteria before placing any trade or bet. If you notice a potential inconsistency, discrepancy, or error in an alert, please report it to our team so we can review and improve the accuracy of our data.
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PredictionHero © 2026 · v0.15.0PredictionHero provides aggregated market data and informational signals only. Nothing on this site constitutes financial, legal, or investment advice. Markets are volatile and speculative. Past performance does not guarantee future results. Always do your own research and consult qualified professionals before making decisions involving risk.