Grade C · 63%RelatedOutcome mapping: same
Kalshi vs Polymarket: Will Republicans win the U.S. Senate in 2026
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.
Kalshi 26.5% vs Polymarket 27.5% on Will Republicans win the U.S. Senate in 2026 — a 1.0 point prediction-market gap.
Live comparison
Kalshi
26.5%
−3.5 pts downPolymarket
27.5%
−1.0 pts down- Disagreement
- 1.0 pts
- Match confidence
- 63%
- Theoretical edge
- none
Side by side
| Metric | Kalshi | Polymarket |
|---|---|---|
| Probability | 26.5% | 27.5% |
| 1h move | 0.0 pts unchanged | 0.0 pts unchanged |
| 24h move | −3.5 pts down | −1.0 pts down |
| 7d move | −10.0 pts down | −8.0 pts down |
| 24h volume | $1.39M | $1.64M |
| Liquidity | $8,699 | $4.42M |
| Spread | 1.0¢ | 1.0¢ |
| Open interest | 10,908,752 | — |
| Closes | Feb 1, 10:00 ET | Nov 3, 23:59 ET |
| Resolution source | https://www.congress.gov/ | — |
| Contract | Open → | Open → |
Probability history
Both venues on one axis, with the gap beneath
KalshiPolymarket
How confident is this match?
Deterministic scoring first; the model may only downgrade
- Title
- 60%
- Entities
- 80%
- Dates
- 30%
- Threshold
- 100%
- Polarity
- 100%
- Rules
- 32%
Deterministic score 63%. 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