Which party will win the Senate in 2026
Leader sits at 56% across 2 bound outcomes, runner-up at 46%. This is a winner-take-all market — the headline is the leader’s price, not an arithmetic mean.
Leader probability
Republican Party
Outcomes
2
winner-take-all
Runner-up
46¢
Democratic Party
Spread
10pp
contested
24h volume
$11K
liquid
Closes
Nov 3, 2026
144 days
Venue
Polymarket
2 bound
30-day trend
Bracket family
How the bracket ladder is priced.
Each row is one outcome on the venue. Sorted by 24h volume — the heaviest book is at the top.
Cluster 1
Which party will win the Senate in 2026
Analysis
This represents the probability that Democrats will control the U.S. Senate after the 2026 midterm elections. The current 51% lean toward Democrats reflects a narrow advantage, with Republicans nearly even at 50%. Senate outcomes depend primarily on which party can flip seats in competitive states and whether national political conditions favor incumbents or challengers. The 2026 midterm elections themselves—scheduled for November 3, 2026—will definitively resolve this question. Leading up to that date, factors like economic conditions, approval ratings, and candidate recruitment in swing states will provide signals that could shift expectations. Currently, polling data and historical midterm patterns suggest slight Democratic resilience, though the narrow margin indicates substantial uncertainty remains.
- ›Democrats currently priced at 51% while Republicans trade at 50%, indicating near-parity rather than Democratic dominance
- ›House probabilities show Democrats at 85% compared to Senate at 51%, suggesting institutional or seat-distribution factors create different dynamics between chambers
- ›Maine Senate race shows Republicans at only 31%, yet national Senate odds remain tight, indicating variance in state-level competitive positions
- ›Kalshi Senate contracts ($29k-$2k daily volume) show lower overall liquidity than House contracts ($42k daily volume), reflecting either less trader interest or greater uncertainty
- ›Resolution date is November 3, 2026—approximately 18 months away with substantial time for economic, political, and candidate-related developments to shift probabilities
Recently closed in election 2026
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These markets stopped trading. Last odds and any captured outcome are shown above — full settlement detail lives at the venue.
Lateral coverage
Thin contract — here's where the deeper coverage is.
This page aggregates 2 contracts (56% headline). At low contract count, the price reflects two participants’ opinions, not a market consensus. The links below are heavier related questions where the orderbook signal is real.
Thicker comparable contracts
In election 2026
Related reading
Midterm Election Odds Shift: Democrats Favored for House, Senate Toss-Up
Democrats are now 78¢ to win the House in 2026, while the Senate remains a coin flip with Republicans at 56¢. The California Governor primary heavily favors Xavier Becerra at 89¢. Peru's election shows Keiko Fujimori solidifying at 93¢.
California & LA Primaries Heat Up: Hilton Surges, Pratt Fades
The California gubernatorial primary and Los Angeles mayoral race are seeing major positioning shifts. Xavier Becerra is the heavy favorite (99¢) in CA, but Steve Hilton surged 7 cents to 96 cents to advance to the runoff. In LA, Spencer Pratt's mayoral bid continues to lose momentum, falling 3 cents to 1 cent, while the Nithya Raman vs Karen Bass matchup solidifies.
How we compute these odds
SimpleFunctions aggregates live prediction-market contracts from Kalshi and Polymarket. Each slug groups contracts that resolve on the same underlying event, identified by venue event_id.
For binary slugs, the headline probability is the liquidity-weighted mid-price across all bound contracts. For multi-outcome slugs (e.g. elections with 3+ candidates), the headline is the leader’s price; we never arithmetically average disjoint outcomes — that would produce a number with no real-world meaning.
Snapshots refresh every 5 minutes during market hours; daily aggregates are computed at 04:00 UTC. The 30-day sparkline is drawn from per-ticker daily means stored in market_indicator_daily; 24h delta and movement events are derived from the same source.
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