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 95.15% on Kalshi; Ed Markey holds the Senate seat at 98.3%, up from 96.5%.

The flow says something different from the price. Mike Minogue, the Republican gubernatorial nominee at 5 cents, down from 6.8, took $88,437 of the event's $89,662 day—98.6% of it—against Healey's $1,224. His leg carries 583,820 contracts of open interest, up from 238,129, to her 59,123. On a race priced 19-to-1, nine of every ten contracts outstanding sit on the underdog.

The Senate book has all but stopped. Under four dollars traded in 24 hours across 21,582 contracts of open interest, all of it on Markey; John Deaton is down to 1.5.

Both winner boards are lopsided, and only Kalshi's governor board trades in size. The margin boards and the vote-share ladder underneath them are where the spread of outcomes lives.

Minogue's leg is the most-traded contract in Massachusetts politics and the one the market gives the least chance. Healey's leg, at nineteen times the price, took $1,224 to his $88,437. Beside it, the rent control initiative is 5.85% to pass, on $908.

Kalshi's Healey vote-percent ladder still spreads the outcomes, though nothing traded on it today: At least 58% at 79%, At least 60% at 62%, At least 62% at 41%. Read across, it implies a Healey share around 61%—a margin in the low twenties. At least 68% is quoted at 54%, out of line with the rungs below it, on a book with no flow to correct it.

Polymarket's top bucket is Democrat 25-30% at 25.5%, ahead of 30-35% at 20.5%, on $570. Kalshi's cumulative ladder answers the same question with a cleaner monotone curve: Healey 23+ points at 61.5%, 26+ at 47.5%.

Watch the Minogue open interest, not his price. 583,820 contracts on a 5-cent leg, up from 238,129, 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 margin boards against each other. Kalshi's governor ladder puts the median Healey margin between 23 and 26 points; Polymarket's modal bucket is 25-30% at 25.5%. 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. Under four 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.