# Massachusetts Democratic Senate Primary Winner

> Ed Markey leads at 70%, runner-up 27% across 2 winner-take-all outcomes — refreshed 1 min ago.

URL: https://simplefunctions.dev/odds/massachusetts-democratic-senate-primary-winner
Updated: 2026-05-09T04:20:39.628Z
Category: general · Topic: election-2026
Status: active
Closes: 2026-09-01

## Headline

- Leader: Ed Markey at 70%
- Runner-up: Seth Moulton at 27%
- Outcomes: 2 (winner-take-all)
- Venue: Polymarket (2 contracts)
- 24h volume: $79

## Bound contracts (2)

| Outcome | Price | 24h | Volume | Venue | Slug |
|---|---|---|---|---|---|
| Ed Markey | 70¢ | +1pp | $49 | polymarket | /markets/massachusetts-democratic-senate-primary-winner-ed-polymarket-0x4808488e54a414ee180be47feebba96166cad42fff4cc5c363733c42b6357d4e |
| Seth Moulton | 27¢ | −2pp | $30 | polymarket | /markets/massachusetts-democratic-senate-primary-winner-set-polymarket-0x6d244daa9ac01837aa4f16ab3b989c21458dcdf8e7417aa2f7221e35d4df7779 |

## 30-day trajectory

| Day | Ed Markey | Seth Moulton |
|---|---|---|
| 2026-04-09 | 87 | 11 |
| 2026-04-25 | 83 | 13 |
| 2026-05-02 | — | 15 |
| 2026-05-03 | 83 | 15 |
| 2026-05-08 | 69 | 26 |

_28 days of price history captured. Each row is the daily mean of intraday 5-min captures._

## What moved the line

- 2026-05-07 · Ed Markey −15pp 83→68¢ · polymarket
- 2026-05-07 · Seth Moulton +9pp 19→28¢ · polymarket
- 2026-05-06 · Seth Moulton +4pp 15→19¢ · polymarket

## Analysis

This probability reflects the current market assessment of which candidate will win the Massachusetts Democratic Senate primary. At 82%, the leading candidate is viewed as the clear favorite, though the 15% probability for the runner-up indicates meaningful uncertainty remains. The primary outcome will depend on voter preferences across the state's urban, suburban, and regional demographics, fundraising totals and spending patterns, and earned media coverage leading up to the primary election. Turnout levels among key Democratic voting blocs—including younger voters, progressive activists, and communities of color—will likely prove decisive. The election date itself will serve as the definitive resolution point, eliminating speculation and determining the actual winner. Until then, shifts in polling data, endorsement announcements, or campaign spending could move these probabilities.

### Key factors

- Current polling gaps between the top two candidates and whether any recent surveys show movement toward or away from the 82% frontrunner
- Endorsement patterns from Massachusetts Democratic establishment figures, labor unions, and progressive organizations that can mobilize specific voter blocs
- Campaign fundraising and spending reports filed with state election authorities, indicating resource disparities in media and field operations
- Turnout modeling and demographic composition of early voting and absentee ballots compared to historical primary patterns
- Scheduled primary election date and whether any major events or developments occur in the final weeks that reshape candidate viability or voter perception

## Methodology

Headline is the **leader's price**, not an arithmetic mean — averaging disjoint winner-take-all outcomes is meaningless. Per-outcome prices come from the venue's last-traded mid; cross-venue values are simple means across contracts on each venue.

## How to use this data

- HTML: https://simplefunctions.dev/odds/massachusetts-democratic-senate-primary-winner
- JSON: https://simplefunctions.dev/api/public/odds?slug=massachusetts-democratic-senate-primary-winner
- Topic hub: https://simplefunctions.dev/predictions/election-2026

## License

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