Michigan Senate 2026

This page is the general election, and three books are pricing it three different ways.

Kalshi's party book has El-Sayed at 61%, its person book at 60.5%, and Polymarket at 62.5%. Two points across three books on the same race, with $3.09M of open interest between them.

Mike Rogers is losing on price and winning on money—on both Kalshi books at once. On the party book the Rogers leg holds $1,033,176 of open interest against El-Sayed's $768,757—34% more, while priced 21 points behind. On the person book: Rogers $548,864, El-Sayed $398,749, a 38% gap. Across both, the 39% side carries $1.58M and the 61% side $1.17M.

Rogers is also outtrading the favorite on both. Party book: $40,410 to $28,092. Person book: $12,482 to $4,080, three to one on the side the market has behind. Polymarket runs the opposite way but on nothing—$923 in the whole book.

A defeated primary candidate still holds six figures. Haley Stevens lost on August 4 and her contract, priced at 0.5%, holds $99,198—more open interest than most entire state-race books in this catalog carry, on an outcome the primary already decided.

The primary margin book Kalshi kept listed has now stopped quoting entirely: zero volume, all rungs at 50 cents, $2.57M of open interest frozen behind it. It has been dropped from this page.

Is Michigan actually the close one? Kalshi's closest-Senate-race book says probably not: Texas leads at 16.5%, then Michigan at 9.85% and Maine at 8.9%, with Georgia at 2.05% and North Carolina at 2.85%. That book holds $257,537 of open interest on $1,382 a day.

Michigan being second on the closest-race board while priced 61-39 on the outcome is internally consistent—a twenty-two-point favorite can still produce a narrow result—but it is worth holding next to the open-interest inversion above. Somebody is positioned for this to be much closer than the headline number.

The spotlight: the two favorites side by side, Kalshi's El-Sayed contract against Polymarket's. 60.5% against 62.5%—the cross-exchange spread on this race is two points and has been inside three points for weeks. The disagreement on Michigan is not about the level. It is about which side the money should be on.

The November 3 seat on three books. Kalshi runs it twice—once as a named-person Categorical that still carries the defeated primary field, once as a two-way—and Polymarket runs a third.

Person book: El-Sayed 60.5%, Rogers 40.5%. Party book: El-Sayed 61%, Rogers 39.5%. Polymarket: El-Sayed 62.5%, Rogers 38.5%. Two points of spread across $3.09M of standing money, and the deepest of the three—the party book at $1.80M—is the one furthest from Polymarket.

National Senate control, for the context this seat sits inside. Michigan is one of the handful of races that decides it, and the market's view of the chamber has to be read against the fact that its Michigan book is priced 61-39 while its Michigan money is stacked 58-42 the other way.

The settled primary margin book has been dropped from this page—it stopped quoting, and a pie chart of eighteen rungs all marked at 50 cents is noise rather than data.

• The 39% side holds $1.58M and the 61% side holds $1.17M. That inversion is now on both Kalshi books simultaneously, and it widened this session on the person book to a 38% gap. Open interest is not a forecast, but a third more money sitting behind the losing side of a twenty-two-point race is the most unusual thing on this page.
• Rogers is outtrading El-Sayed three to one on the person book. $12,482 against $4,080, and $40,410 against $28,092 on the party book. Both directions of flow point the same way and neither has moved the price.
• South Carolina just ran this experiment. In the August 25 runoff the money was on Ralph Norman all week—more volume, deepest margin legs on narrow-Norman wins—and he lost by five. Volume was not information there. Michigan is the same shape at ten times the size.
• $99,198 parked on a candidate who lost in August. Haley Stevens at 0.5%. The person book carries the defeated primary field and the standing money has not unwound.
• Michigan sits second on the closest-race board at 9.85%. Behind Texas at 16.5%. A book that prices this race 61-39 and simultaneously ranks it the second-likeliest nail-biter is telling you the distribution is wide even if the median is not close.
• The party book is the one to watch, not the person book. It carries $1.80M of the $3.09M and it is the furthest from Polymarket. When those two converge, one of them moved for a reason.