Grade C · 68%RelatedOutcome mapping: same

Kalshi vs Polymarket: Will Josh Stein win the 2028 Democratic presidential nomination

Two contracts on the same event, priced by two separate crowds. Where they disagree, one of them is wrong — or the contracts are not quite the same question.

Live comparison
Kalshi
4.8%
−0.2 pts down
Polymarket
0.1%
0.0 pts unchanged
Disagreement
4.7 pts
Match confidence
68%
Theoretical edge
none

Side by side

MetricKalshiPolymarket
Probability4.8%0.1%
1h move+0.1 pts up0.0 pts unchanged
24h move−0.2 pts down0.0 pts unchanged
7d move+0.1 pts up—
24h volume$131K$9,664
Liquidity$94.00$1.91M
Spread0.2¢0.1¢
Open interest4,301,020—
ClosesNov 7, 10:00 ETNov 7, 23:59 ET
Resolution sourcehttps://democrats.org/—
ContractOpen →Open →

Probability history

Both venues on one axis, with the gap beneath
KalshiPolymarket
Kalshi and Polymarket implied probability for Will Josh Stein win the 2028 Democratic presidential nomination. Kalshi moved from 5% to 5%. Times shown in EST.0%20%40%60%80%100%22:00 ET02:53 ET08:47 ET14:41 ET20:35 ET

How confident is this match?

Deterministic scoring first; the model may only downgrade
Title
64%
Entities
20%
Dates
100%
Threshold
100%
Polarity
100%
Rules
65%

Deterministic score 68%. Not yet semantically verified.

These contracts have not been semantically verified yet, so no rule-by-rule comparison is available. The grade rests on deterministic scoring alone.

Theoretical cross-market edge

Grade A pairs only, from executable book prices with depth simulation
Theoretical edge is calculated only for Grade A pairs, where the two contracts appear materially equivalent for settlement analysis. This pair is graded C, so the venues are compared for probability and sentiment only.

Why are these diverging?

Explanation pending

An evidence-grounded explanation is written once this market gathers enough confirmed price and trade evidence. Every number on this page is already live.

Event timeline

No timeline events yet

Timeline entries appear once price or trade activity crosses a reporting threshold.

Notable trades on both venues

Past 24 hours, ranked by notional
MarketVenueTimeSidePriceSizeNotionalBefore+5 minMoveImpact
Will Josh Shapiro be the Democratic Presidential nominee in 2028?Politics · Kalshi ↗Kalshi01:32 ET19 h agoNo sell95.3%121K$115K———Normal
Will Josh Shapiro be the Democratic Presidential nominee in 2028?Politics · Kalshi ↗Kalshi01:28 ET19 h agoNo sell95.1%2.0K$1,902———Normal
Will Josh Shapiro be the Democratic Presidential nominee in 2028?Politics · Kalshi ↗Kalshi03:45 ET17 h agoNo sell95.2%1.0K$952———Normal
Will Josh Shapiro be the Democratic Presidential nominee in 2028?Politics · Kalshi ↗Kalshi01:28 ET19 h agoNo sell95.1%456.6$434———Normal
Will Josh Shapiro be the Democratic Presidential nominee in 2028?Politics · Kalshi ↗Kalshi01:28 ET19 h agoNo sell95.1%276$262———Normal