Prices as of August 25, 2026, 3:20 p.m. Eastern. Record compiled from more than 40 dated sources; see the sourced record file for every citation.
Ed Markey turned 80 in July. Suffolk University, polling 500 likely Democratic-primary voters for the Boston Globe from August 13 to 16, asked what that meant to them. In the published crosstabs, 11.2% said they will not vote for him because of his age and another 33.4% said it makes them less likely to. That is 44.6% of the people choosing the Democratic nominee for U.S. Senate on Tuesday, September 1, saying his age counts against him. The same poll has Markey beating Rep. Seth Moulton, who is 47, by 52.2% to 37.6%.
The Globe's Samantha J. Gross and Anjali Huynh found the voter who explains the gap. Adam Tessier, a 39-year-old accountant from Dracut, told them on August 18 that aging politicians worry him. Then: "I'll vote for the old man."
On Kalshi, where a price in cents is a probability, a contract that pays $1 if Markey is the nominee was quoted at 94.2 cents by buyers and 94.6 by sellers at 3:20 p.m. Eastern on August 25, a middle price of 94.4 cents, or about a 94% chance. In sportsbook terms that is roughly -1,690. Moulton's contract sat at 5.5 cents on the buy side and 6.1 on the sell side, about 5.8 in the middle: a 6% shot, or about +1,620. Politico Magazine called the race, on August 22, "a real test of what the party values more: age or ideology." The people with money on it answered weeks ago.
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The Board
As of August 25, 2026, 3:20 p.m. Eastern (Kalshi, cents = probability):
| Outcome | Price | Reads as |
|---|---|---|
| Ed Markey | 94.4¢ | about 94% (≈-1,690 in sportsbook terms) |
| Seth Moulton | 5.8¢ | about 6% (≈+1,620) |
The prices are the midpoint between what buyers offer and what sellers ask. Markey's contract has about 209,600 contracts open of 332,600 traded; Moulton's, 259,500 of 359,400, and his was the busier one on Tuesday, 11,700 contracts in a range of 4.7 to 9.0 cents. Polymarket, pulled at the same 3:20 p.m. moment, had Markey at 95 cents and Moulton at 5.5 on about $120,000 of total trading. Its thin side market on Markey's winning margin has a 10-to-15-point win as the most-bought answer, at 24.5 cents, right where Suffolk's 14.6-point gap sits, on $344 of trading.
What the Models Think
We also asked a panel of AI models the same question without showing them the price, only the sourced record below. Six of the panel's eight seats ran this board. Blended together, their middle answer put Markey at 94%, right where the 94.4-cent market sits, and the widest gap between any two models was 3 points. The interesting part is why they agree. Each started from the same two facts: a sitting senator with 82% approval among his own primary voters almost never loses renomination, and no nonpartisan August poll has him ahead by less than 14. One model: "Markey leads by 14–26 points in the two most reliable August polls with 82% approval among Democratic-primary voters one week before the election; such late double-digit leads essentially never reverse." They also named the one thing that would move them: a final independent poll with the margin inside five points.
These are model estimates, not predictions. The market has real money behind it; the panel has only the record.
How A Six-Point Race Became A Fourteen-Point Lead
Markey has been in Congress since 1976 and in the Senate since 2013. Moulton, a Marine who served in Iraq, has held the North Shore's 6th District since 2015 and gave up the seat to run. In the spring this looked like a contest: Emerson College had it 37% to 32% on May 3 and 4, with Moulton ahead 38% to 32% among unenrolled voters, the independents who can take a Democratic ballot here. Markey's Kalshi price bottomed at 62 cents on July 20, two weeks after the first debate. A price in the low 60s says the market thought this was a real fight.
Then the August polls landed. UMass Amherst and WCVB, in the field August 5 to 12, put Markey up 54% to 28%, 60% to 32% with leaners. Suffolk followed. On August 18, the day both published, Markey's contract jumped from 83 to 90 cents and Moulton's fell from 17 to 8. Suffolk's David Paleologos told the Globe the polling "has never suggested the primary was close."
The reason age does not decide it is in the same crosstabs. Asked which candidate is more progressive, Suffolk's respondents said Markey, 47.8% to 22.4%; his approval among Democratic-primary voters sat at 82% to 14%. Warren, Sanders, and on August 20 Alexandria Ocasio-Cortez endorsed him; Gov. Maura Healey endorsed nobody. Moulton's biggest name was the Boston Globe editorial board, which backed him on August 18 under the closing line "The future must be now."
Massachusetts runs a semi-closed primary: registered Democrats and unenrolled voters may take the Democratic ballot, early in-person voting opened on August 22, and plurality wins. The nominee faces Republican John Deaton in November on the map that decides Senate control, one of every Senate board we track. If cents-as-probability is new to you, how a Senate race trades on Kalshi is a five-minute read.
Epstein, "Under The Political Bus," And An iPad
The second debate, on Boston 25 and GBH on August 3, is where the campaign turned ugly and the price started climbing. Moulton asked, per GBH, "Why would you even take a meeting with a lobbyist on behalf of Jeffrey Epstein?" Markey: "At no time did I ever meet with anyone related to Epstein on anything that has to do with Epstein at all." Two days later he called it "absolutely inaccurate. It is desperate. It is an attempt to engage in the politics of smear." PolitiFact rated Moulton's claim Mostly False on August 6: the basis was a December 2015 email in which a lobbyist told Epstein he had briefed "Senator Ed Markey" on a Senegal matter, and "nothing in the email showed that Markey knew Epstein was involved." WBUR's fact-check added that Moulton himself accepted $2,000 from one of the same lobbyists. Markey's contract went from 73 cents on debate night to 80 on the day the rating published.
The trans-athlete fight cuts the other way. Moulton told the New York Times in November 2024 that he did not want his daughters "getting run over on a playing field by a male or formerly male athlete." Markey said he had thrown trans kids "under the political bus," and at the second debate Moulton apologized: "I'm sorry if my comments hurt you. That was not my intention." At the third debate on August 20, per Boston.com, Markey pressed again: "Congressman Moulton threw those kids under the political bus after the election of 2024. He just turned them into political fodder that made them afraid." UMass found 67% of Democratic-primary voters less likely to back a candidate who "expressed positions opposing transgender rights."
The war exchange split at the fact-checkers: Moulton's "You voted to send people like me, thousands of young Americans" to Iraq was rated accurate, and Markey's charge that Moulton voted for "a $1 trillion budget" for war in Iran was rated mostly incorrect. The most replayed moment was smaller. Asked about artificial intelligence, Markey said, "I use whatever is inside of my iPhone and my iPad, whatever comes up and I don't know what companies my iPad might be using." Moulton: "With all due respect, senator, if you don't even know what you're using on your phone or your iPad, this is why we need a new generation of leaders to regulate these technologies." Markey answered that "it doesn't make any difference whether it's called Siri or it's called Claude." Moulton carried it to CBS's Face the Nation on August 23: "He's been in Washington for 50 years, Margaret." Markey's price on the Friday after the debate was 92.9 cents. On Monday it was 94.4.
Money is the one column Moulton wins: Federal Election Commission filings through August 12 show him with $1,835,336 on hand to Markey's $1,348,676. The union-backed Commonwealth Together PAC has spent six figures attacking Moulton's roughly $13 million net worth and stock holdings, the Washington Examiner reported on August 13, and Markey has not disavowed it despite signing Bernie Sanders' letter declaring that "Getting super PAC money and dark money out of Democratic primaries is not some pie in the sky dream." PolitiFact rated the PAC's allegation that "Moulton voted with Republicans to thank ICE" Mostly False in April. On the other side, a dark-money group led by a Moulton donor has run "Pass the torch" ads against Markey's tenure since spring.
What Moves The Price From Here
- A last public poll. Nothing has published since PPP's partisan-sponsored August 17 and 18 survey. A nonpartisan number in single digits would knock cents off Markey; another 14-plus lead pins him in the mid-90s through election day.
- Who shows up. Secretary of State William Galvin said on August 22 that this matchup is not expected to drive early turnout. A surge of unenrolled voters, where Emerson had Moulton ahead, is the only structural path the models could find for him.
- Moulton's closing week. About $490,000 more in the bank, the Globe's endorsement, and a national television hit. A price in the mid-90s says the market expects that to buy margin, not the nomination.
This one settles on Tuesday, September 1, 2026.
Hero illustration: OddsShopper, in the house collage style. Ed Markey photo by U.S. House of Representatives, licensed Public domain; Seth Moulton photo by United States Govrnment, licensed Public domain; photos cropped, toned, and composited. Prices quoted are live Kalshi market prices as of August 25, 2026, 3:20 p.m. Eastern, and will keep moving until this market settles after the Tuesday, September 1, 2026 vote. Kalshi is a CFTC-regulated event-contract exchange (18+; availability varies by state). OddsShopper covers prediction markets as an independent analyst: any model or panel figures referenced are model estimates, not predictions of fact and not financial advice. This article does not advocate for or against any candidate or party. Trading involves risk; contracts can go to zero.
