2026 Massachusetts · U.S. House
MA-03 House race odds
As of Oct 2, 2026, prediction markets give Democrat Lori Trahan a 98% chance of winning the 2026 race for MA-03 over Republican Gary Grossi (Kalshi 97%, Polymarket 98%).
Updated · prices refresh every 10 minutes
- Market rating
- Safe D
- Kalshi (D / R)
- 97.4% / 2.6%
- Polymarket (D / R)
- 97.6% / 2.4%
- Gap between exchanges
- 0.2 pts
- Election Day
- Nov 3, 2026 (32 days)
Price history
Democratic odds are essentially unchanged since Oct 2, 2026.
Every candidate, by exchange
Each exchange's prices rescaled to add up to 100%. Kalshi prices are the bid–ask midpoint; Polymarket prices are its displayed price.
Kalshi open market ↗
| Outcome | Chance | Volume |
|---|---|---|
| Lori Trahan (D) | 97.4% | $827 |
| Gary Grossi (R) | 2.6% | $1K |
Polymarket open market ↗
| Outcome | Chance | Volume |
|---|---|---|
| Lori Trahan (D) | 97.6% | $12K |
| Gary Grossi (R) | 2.4% | $11K |
Questions about this race
Who is favored to win the 2026 MA-03 House race?
As of Oct 2, 2026, prediction markets give Democrat Lori Trahan a 98% chance of winning the 2026 race for MA-03 over Republican Gary Grossi (Kalshi 97%, Polymarket 98%).
What do Kalshi and Polymarket say?
Kalshi: Democrats 97%, Republicans 3%. Polymarket: Democrats 98%, Republicans 2%. The two exchanges differ by 0.2 points.
How have the odds moved this week?
Democratic odds are essentially unchanged since Oct 2, 2026.
When is the 2026 election?
Election Day is Nov 3, 2026, 32 days from now.
Other Massachusetts races in 2026
- Massachusetts GovernorD 96%
- MA-01 HouseD 97%
- MA-02 HouseD 96%
- MA-04 HouseD 98%
- MA-05 HouseD 98%
- MA-06 HouseD 97%
- MA-07 HouseD 98%
- MA-08 HouseD 98%
- MA-09 HouseD 97%
- Massachusetts SenateD 98%
Closest House races in 2026
Data
Price history (JSON)All 2026 races (JSON)All 2026 races (CSV)2026 dashboardMethodology
Cite as: Parlay the People, “2026 MA-03 House race,” https://parlaythepeople.com/2026/house/ma-3/, accessed Oct 2, 2026. Prediction-market prices are crowd forecasts, not certainties, and nothing here is betting or investment advice.