As of September 9, 2026, the Democratic side is favored in the Massachusetts Senate Race 2026 market, at an implied probability of about 97% (97¢ per contract on Kalshi). This contract settles on which party wins the race, not on any individual candidate; the exchanges list it under Ed Markey’s name. Live prices below are pulled directly from Kalshi and Polymarket.
Kalshi vs Polymarket: Massachusetts Senate Odds
The same outcome often trades at different prices on different exchanges.
| Outcome | Kalshi | Polymarket | Gap |
|---|---|---|---|
| Ed Markey | 97% | 97% | 0.0 pts |
| John Deaton | 1.4% | 2.5% | 1.1 pts |
Massachusetts Senate Odds on Kalshi
| Outcome | Implied probability | Price | Bid / Ask |
|---|---|---|---|
| Ed Markey | 97% | 97¢ | 97¢ / 97¢ |
| John Deaton | 1.4% | 1¢ | 1¢ / 3¢ |
Each row above is a contract on a party holding the seat. The names are the exchange’s own labels for those contracts and can lag the actual candidate field.
Massachusetts Senate Odds on Polymarket
| Outcome | Implied probability | Price | Bid / Ask |
|---|---|---|---|
| Ed Markey (D) | 97% | 97¢ | 96¢ / 97¢ |
| John Deaton (R) | 2.5% | 2¢ | 1¢ / 4¢ |
Where Massachusetts Senate Odds Have Been
The Democratic side last closed at 97% (Sep 9, 2026). That is -2 points since Aug 12, 2026 (99%). Since Mar 16, 2026, the earliest daily price we track for this market, it has moved +2 points from 95%.
| Date | Kalshi |
|---|---|
| Mar 16, 2026 | 95% |
| Jul 25, 2026 | 97% |
| Aug 6, 2026 | 98% |
| Aug 22, 2026 | 96% |
| Sep 2, 2026 | 98% |
| Sep 9, 2026 | 97% |
Across that period the market ranged from a low of 95% on Mar 16, 2026 to a high of 99% on Aug 12, 2026. Prices are daily closes from Kalshi.
About the Massachusetts Senate Race
The markets price this race at party level — Democratic vs Republican — rather than by individual candidate; candidate-level markets typically appear after the primaries decide who is running. Election Day is November 3, 2026. This market is scheduled to close around 2027-11-03, settling when the winner is official.
Market Odds vs Polls
Polls measure who people say they support; prediction market odds measure where traders put real money. Polling averages update every few days or weeks, while market prices react to news within minutes — including primary results, debate moments, and fundraising reports. Markets also price primary races and nominee fields before pollsters survey them. Neither is infallible: polls carry sampling error, and thin markets can be moved by a few large trades. Historically, market prices in aggregate have been well-calibrated — a 70% favorite wins about 70% of the time.
About This Market
This market will resolve according to the winner of the 2026 midterm Massachusetts U.S. Senate election, inclusive of any run-offs. A candidate shall be considered to represent a party in the event that he or she is the nominee of the party in question. Candidates other than the Democratic or Republican nominee (e.g., Greens, Libertarian, independent) may be added at a later date. Candidates who run as independents…
How to Trade This Market
Kalshi (CFTC-regulated, all 50 states for political markets) and Polymarket (lowest fees, iOS in 49 states) both offer event markets; see our head-to-head comparison or run your trade through the fee calculator before placing it. New to event contracts? Start with how prediction markets work.
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Common Questions
Which party is favored in the Massachusetts Senate Race 2026 market?
As of September 9, 2026, the Democratic side is favored, at an implied probability of about 97% (a 97¢ contract on Kalshi). The contract settles on which party wins the race rather than on a named candidate, though the exchanges display it under Ed Markey’s name. Prices move constantly as traders buy and sell; the tables on this page show the latest synced prices.
Where can I trade the Massachusetts Senate market?
This market trades on both Kalshi and Polymarket. Kalshi is a CFTC-regulated exchange available in all 50 states for political markets; Polymarket US is open to iOS users in 49 states. See our platform reviews for fees and details.
How do prediction market odds work?
Contracts pay $1 if the outcome happens and $0 if it does not, so the price is the market’s implied probability: a 62¢ contract means traders collectively price a 62% chance. Odds come from real money changing hands, not from polls or pundits.
Who is running in the Massachusetts Senate Race 2026?
These markets currently price the race at party level (Democratic vs Republican) rather than by individual candidate. Candidate-level markets usually appear once the primaries settle the field.
When will the Massachusetts Senate market settle?
Election Day is November 3, 2026; the market is scheduled to close around 2027-11-03. Contracts settle at $1 or $0 once the outcome is officially determined.
Prices synced September 9, 2026 from public Kalshi and Polymarket market data by Arthur Angelo. Odds move constantly; check the exchange for execution prices. This page is informational — not investment advice. PredictionScout may earn commissions from platform links; see our affiliate disclosure. More markets: all live odds pages.