Market comparison
How many House seats will Democrats win in Iowa?
2 venues · 6 outcome rows · 3 comparable lines · event identity linked · 0 verified parity · active
Polymarket
Open venue ↗5 outcomes · $27K reported volume
Observed 1m ago
Recorded venue end date: Nov 4, 2026
Kalshi
Open venue ↗4 outcomes · $18K reported volume
Observed 10s ago
Recorded venue end date: Nov 3, 2027
Known rule differences between venues
- Seat counts depend on when races are called; venues use different settlement deadlines for uncalled seats.
A shared identity alone does not make a price difference executable.
| Outcome | Polymarket | Kalshi | Difference |
|---|---|---|---|
0 Partial parityPayoffs match in ordinary outcomes; see the rule differences above. | 1.3 pp | ||
1 Partial parityPayoffs match in ordinary outcomes; see the rule differences above. | 1.0 pp | ||
2 Partial parityPayoffs match in ordinary outcomes; see the rule differences above. | 3.5 pp | ||
3 Not alignedNo persisted outcome identity connects these venue contracts. | — | — | |
4 Not alignedNo persisted outcome identity connects these venue contracts. | — | — | |
Above 2 Not alignedNo persisted outcome identity connects these venue contracts. | — | — |
0
Partial parityPayoffs match in ordinary outcomes; see the rule differences above.
Polymarket
Kalshi
Price difference 1.3 pp
1
Partial parityPayoffs match in ordinary outcomes; see the rule differences above.
Polymarket
Kalshi
Price difference 1.0 pp
2
Partial parityPayoffs match in ordinary outcomes; see the rule differences above.
Polymarket
Kalshi
Price difference 3.5 pp
3
Not alignedNo persisted outcome identity connects these venue contracts.
Polymarket
Kalshi
—
4
Not alignedNo persisted outcome identity connects these venue contracts.
Polymarket
Kalshi
—
Above 2
Not alignedNo persisted outcome identity connects these venue contracts.
Polymarket
—
Kalshi
Prices are shown as percentages of a $1 payout. “pp” means percentage points. A dash means data is unavailable.