Aug 11, 2026
Probability rose from 94.0% to 97.0% — a 3.1-point move over the past day.
MA-05 House Election Winner: Odds & Probability
Markets price a Democratic hold in Massachusetts’ 5th congressional district at 96.4%, ahead of the 2026 midterm elections on Nov 4, 2026.
96.4%0.0 pts 24h
Will the Democratic Party win the MA-05 House seat?
Updated · Volume $37.3K
| Outcome | Probability | 24h |
|---|---|---|
| Will the Democratic Party win the MA-05 House seat? | 96.4% | 0.0 |
| Will the Republican Party win the MA-05 House seat? | 2.3% | +0.1 |
| Will B win the MA-05 House seat? | 0.0% | 0.0 |
| Will A win the MA-05 House seat? | 0.0% | 0.0 |
| Will C win the MA-05 House seat? | 0.0% | 0.0 |
| Will D win the MA-05 House seat? | 0.0% | 0.0 |
| Will another party win the MA-05 House seat? | 0.0% | 0.0 |
| Will E win the MA-05 House seat? | 0.0% | 0.0 |
The Democratic Party is near-certain to retain the seat, while all other outcomes are long shots.
Context
Aug 10, 2026
Probability rose from 94.5% to 96.5% — a 2.0-point move over the past day.
The probability of a Democratic victory has traded, resting at 96.4% as of 9 min ago. A change of 0.0 pts in the past day points to stable confidence in the incumbent party. The contract settles based on the party affiliation of the winning candidate in the 2026 U.S. House election for Massachusetts’ 5th district. A candidate’s party is determined by their ballot-listed affiliation, or—if none appears—by the party with which they have most recently expressed an intent to caucus. In case of ambiguity, the market resolves to official Federal Election Commission results; otherwise, it follows a consensus of credible election reporting. The main catalyst is the election itself on Nov 4, 2026 and the subsequent calling of the race. Any change in the consensus about which party is likely to win—whether driven by polling, candidate announcements, or district-level developments—could shift the odds. Formal resolution relies on the sources above, so the timing of conclusive reporting determines exactly when the contract settles.
FAQ
How is a candidate’s party determined for this market?
It is based on their ballot-listed affiliation. If a candidate has no such affiliation, the market uses the party with which they most recently expressed an intent to caucus in the House.
What happens if the election result is disputed or ambiguous?
The market resolves per a consensus of credible reporting. If consensus cannot be reached, it defaults to the official results published by the Federal Election Commission.
Does this market cover the primary elections, or only the general?
Only the general election outcome for the MA-05 seat. The party of the winner in the November 2026 midterm election determines settlement.
What if an independent or third-party candidate wins?
That candidate’s party is assigned based on the party they caucus with, as per the market’s rules. If they caucus with neither Democrats nor Republicans, the market would resolve to a different outcome, though such scenarios are historically rare.
When will the market resolve?
After the votes are counted and the race is conclusively called by credible sources or the FEC. This could happen on election night or later, depending on how close the contest is.
Data: Polymarket · Methodology · Not financial advice