TOTAL VOLUME:
$54.3b
24H VOL:
$198,896,558
OPEN INTEREST:
$1,191,591,877
500,572
Markets across
13,691
events
MATCHED EVENTS:
1,797
PLATFORM COVERAGE:
4
Polymarket:
51%
VS.
Kalshi:
49%
S&P 500 (SPX) Up or Down on April 9?
Volume:
$237,510
Outcome
Chance %
Price
Liquidity
Volume
24h
7d
Open Interest
Ends in
Result
Trade
Description
These markets track whether the S&P 500 index closes higher or lower on April 9, 2026 compared to the prior trading day (Polymarket) or whether it closes above specific price thresholds (Kalshi). Both platforms use the official S&P 500 closing price as the settlement value, sourced from Wall Street Journal data.
PredictionHero - Resolution Divergence Alerts (RDA)
Divergence Detected
Issue:
Market type divergence: Polymarket uses relative directional logic (vs prior day close), while Kalshi uses absolute price level logic (fixed thresholds). Both source the same underlying data (April 9, 2026 SPX close) but apply incompatible resolution frameworks.Hero Tip:
These markets require different trading strategies. Polymarket rewards directional prediction relative to April 8 close; Kalshi rewards absolute price forecasting. Do not assume one resolves the same way as the other. Confirm the April 8, 2026 SPX close before mapping Polymarket outcomes to Kalshi contract payoffs.Critical Divergence Points:
- Polymarket: Directional comparison market. Resolves Up/Down based on whether April 9 close is higher or lower than the most recent prior trading day close (typically April 8, unless a holiday). Resolves 50-50 on equality or no trade. Source: Wall Street Journal Historical Prices.
- Kalshi: Absolute level market with 50 binary contracts. Each contract resolves Yes if end-of-day SPX on April 9, 2026 exceeds a specific threshold ranging from 5849.9999 to 7324.9999 in 25-point increments. No directional or comparative logic; purely threshold-based.
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 · v0.13.0PredictionHero 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.