TOTAL VOLUME:

$134b

24H VOL:

$103,397,351

24H TRANSACTIONS:

2,388,728,490

OPEN INTEREST:

$1,410,176,180

399,592

Markets across

30,097

events

MATCHED EVENTS:

2,622

PLATFORM COVERAGE:

5

Polymarket:

39%

VS.

Kalshi:

61%

BETA

Science and Technology

S&P 500 (SPX) Up or Down on April 8?

polymarket

kalshi

S&P 500 (SPX) Up or Down on April 8?

Volume:

$519,875

S&P 500 (SPX) Up or Down on April 8?

- Polymarket

S&P 500 (SPX) Up or Down on April 8? - Polymarket

1W

News

Positive

Negative

Neutral

Hover marker for details

Vol.

·

Resolved Apr 9, 2026

Closed: Apr 8, 4:00 PM EST

polymarket

Polymarket

Markets

Outcome

Trade

Chance %

Price

Spread

Liquidity

Volume

24h

7d

Open Interest

Ends in

Result

polymarket

S&P 500 (SPX) Up or Down on April 8?

100%

Yes 100¢

No 0¢

—

N/A

$314,111

N/A

N/A

N/A

Settled

Yes

kalshi

6,775 or above

100%

Yes 100¢

No 0¢

—

N/A

$37,421

N/A

N/A

$7,262

Settled

Yes

kalshi

6,750 or above

100%

Yes 100¢

No 0¢

—

N/A

$28,210

N/A

N/A

$12,332

Settled

Yes

kalshi

6,725 or above

100%

Yes 100¢

No 0¢

—

N/A

$7,759

N/A

N/A

$5,846

Settled

Yes

kalshi

6,650 or above

100%

Yes 100¢

No 0¢

—

N/A

$5,456

N/A

N/A

$1,978

Settled

Yes

kalshi

6,700 or above

100%

Yes 100¢

No 0¢

—

N/A

$5,062

N/A

N/A

$4,718

Settled

Yes

kalshi

6,625 or above

100%

Yes 100¢

No 0¢

—

N/A

$2,449

N/A

N/A

$1,276

Settled

Yes

kalshi

6,600 or above

100%

Yes 100¢

No 0¢

—

N/A

$2,162

N/A

N/A

$2,093

Settled

Yes

kalshi

6,675 or above

100%

Yes 100¢

No 0¢

—

N/A

$1,801

N/A

N/A

$1,358

Settled

Yes

kalshi

5,850 or above

100%

Yes 100¢

No 0¢

—

N/A

$1,629

N/A

N/A

$1,629

Settled

Yes

kalshi

6,275 or above

100%

Yes 100¢

No 0¢

—

N/A

$1,440

N/A

N/A

$1,440

Settled

Yes

kalshi

6,450 or above

100%

Yes 100¢

No 0¢

—

N/A

$1,307

N/A

N/A

$1,099

Settled

Yes

kalshi

6,525 or above

100%

Yes 100¢

No 0¢

—

N/A

$763

N/A

N/A

$727

Settled

Yes

kalshi

6,550 or above

100%

Yes 100¢

No 0¢

—

N/A

$670

N/A

N/A

$643

Settled

Yes

kalshi

6,500 or above

100%

Yes 100¢

No 0¢

—

N/A

$370

N/A

N/A

$369

Settled

Yes

kalshi

6,350 or above

100%

Yes 100¢

No 0¢

—

N/A

$188

N/A

N/A

$178

Settled

Yes

kalshi

6,425 or above

100%

Yes 100¢

No 0¢

—

N/A

$179

N/A

N/A

$179

Settled

Yes

kalshi

6,300 or above

100%

Yes 100¢

No 0¢

—

N/A

$129

N/A

N/A

$129

Settled

Yes

kalshi

6,150 or above

100%

Yes 100¢

No 0¢

—

N/A

$126

N/A

N/A

$126

Settled

Yes

kalshi

6,325 or above

100%

Yes 100¢

No 0¢

—

N/A

$125

N/A

N/A

$124

Settled

Yes

kalshi

6,225 or above

100%

Yes 100¢

No 0¢

—

N/A

$115

N/A

N/A

$115

Settled

Yes

kalshi

6,075 or above

100%

Yes 100¢

No 0¢

—

N/A

$114

N/A

N/A

$114

Settled

Yes

kalshi

6,250 or above

100%

Yes 100¢

No 0¢

—

N/A

$114

N/A

N/A

$114

Settled

Yes

kalshi

6,100 or above

100%

Yes 100¢

No 0¢

—

N/A

$111

N/A

N/A

$111

Settled

Yes

kalshi

6,125 or above

100%

Yes 100¢

No 0¢

—

N/A

$110

N/A

N/A

$110

Settled

Yes

Total markets: 25 of 61

Description

This market will resolve to "Up" if the official S&P 500 Index closing price for S&P 500 (SPX) on Wednesday, April 8, 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 Wednesday, April 8, 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 resolves based on absolute index level thresholds (50 binary outcomes at 25-point intervals). These frameworks cannot produce equivalent outcomes for the same underlying event.Hero tip: Do not assume these markets will settle identically. On Polymarket, a 0.5% move up resolves YES; on Kalshi, only moves that cross specific threshold levels (5850, 5875, 5900, etc.) resolve YES. A SPX close of 5860 on April 8 would resolve YES on Polymarket if prior close was below 5860, but may resolve NO on Kalshi if the prior close was already above 5850. Arbitrage risk is extreme—verify the prior trading day close and Kalshi's exact threshold structure before trading.

Critical divergence points:

Polymarket: Outlier: Resolves based on directional comparison between April 8, 2026 closing price and the most recent prior trading day closing price. YES if April 8 close is higher, NO if lower, 50-50 if equal. Source is Wall Street Journal Historical Prices. Key quote: 'This market will resolve to Up if the official S&P 500 Index closing price for S&P 500 (SPX) on Wednesday, April 8, 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 on April 8, 2026 end-of-day. Contains 50 separate binary outcomes, each resolving YES if SPX closes above a specific threshold (5850, 5875, 5900, 5925, ... up to 7325). Each threshold is independent; multiple outcomes can resolve YES simultaneously. Key quote: 'If the end-of-day S&P 500 index value on April 08, 2026 is above 5849.9999, 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.