Massachusetts 2026 — after the primaries

The September 8 primaries settled and Massachusetts is back to two general elections nobody expects to be close. Maura Healey holds the governorship at 96% on Kalshi; Ed Markey holds the Senate seat at 96.5%. Neither number has moved meaningfully in months.

The flow says something different from the price. Mike Minogue, the Republican gubernatorial nominee at 6.8 cents, took $758 of the event's $1,186 day—64% of it—against Healey's $428. His leg carries 238,129 contracts of open interest to her 40,476. On a race priced 14-to-1, six of every seven contracts outstanding sit on the underdog.

The Senate book has all but stopped. Fourteen dollars traded in 24 hours across 9,025 contracts of open interest, and every cent of it was on John Deaton at 2.7.

Both winner boards are closed. What still moves is the margin, and the vote-share ladder underneath it.

Minogue's leg is the most-traded contract in Massachusetts politics and the one the market gives the least chance. Healey's leg, at fourteen times the price, trades at half the volume.

Kalshi's Healey vote-percent ladder is the only Massachusetts board with a genuine spread of outcomes: At least 58% at 78%, At least 62% at 44%, At least 68% at 7%. Read across, it implies a Healey share somewhere around 61 to 62%—a margin in the low twenties, which is roughly where Polymarket's margin board centres too.

Polymarket spreads nine buckets from 0-5% to 40%+ with no favourite above 19%. Kalshi's cumulative ladder answers the same question with a cleaner monotone curve.

Watch the Minogue open interest, not his price. 238,129 contracts on a 6.8-cent leg is either a very large directional wager on a polling miss or, more likely, inventory that sellers opened and have not closed. If the price holds while open interest falls, it was the latter.

Watch the vote-share ladder against the margin board. Kalshi implies Healey near 61 to 62%; Polymarket's modal margin bucket is 25-30%. Those two are roughly consistent, and a divergence between them would be the first real information Massachusetts produces this cycle.

Watch whether the Senate book wakes up at all. Fourteen dollars a day on a statewide Senate race is a market that has stopped functioning as a price. Any sustained volume there is worth a second look.