The closely matched Polymarket bins around 2.65M–2.95M votes reflect uncertainty over participation in Massachusetts’s low-competition 2026 Senate contest between incumbent Democrat Ed Markey and Republican John Deaton. Recent polling shows Markey leading by roughly 23–29 points in a solidly Democratic state, producing limited general-election enthusiasm after Markey’s September primary victory over Seth Moulton. Massachusetts Secretary of State William Galvin has indicated the primary generated no unusual turnout surge, consistent with typical midterm drop-off patterns. Traders are weighing standard factors including early voting volumes beginning October 17, mail ballot returns, and base voter mobilization in a race widely viewed as safe for the incumbent. No major late developments have yet separated the leading ranges.