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 March 17?
Volume:
$300,840
Outcome
Chance %
Price
Liquidity
Volume
24h
7d
Open Interest
Ends in
Result
Trade
Description
This event group tracks whether the S&P 500 index closes higher or lower on March 17, 2026 compared to the prior trading day. Polymarket frames this as a directional comparison (Up vs Down), while Kalshi offers 60 individual binary contracts tied to specific price thresholds. Both markets resolve based on official closing prices from the S&P 500 Index.
PredictionHero - Resolution Divergence Alerts (RDA)
Divergence Detected
Issue:
Polymarket uses relative price movement (day-over-day comparison) while Kalshi uses absolute price thresholds. These are structurally incompatible settlement frameworks, not merely different data sources or timing.Hero Tip:
Polymarket UP/DOWN is a directional bet; Kalshi thresholds are level-based bets. A day that closes higher than the prior day (Polymarket UP) could still resolve NO on many Kalshi contracts if the absolute price is below their respective thresholds. Treat these as separate markets with different risk profiles.Critical Divergence Points:
- Polymarket: Relative directional market. Resolves UP if March 17 close exceeds prior trading day close; DOWN if lower; 50-50 if equal. Source: WSJ Historical Prices. Settlement is binary directional comparison, not absolute price level.
- Kalshi: 60 separate absolute threshold contracts. Each resolves YES only if end-of-day SPX exceeds a specific price barrier (5874.9999 to 7349.9999). No comparison to prior day; purely absolute level-based settlement.
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.