Iowa Senate 2026

Iowa is still the closest of the Senate races this catalog tracks: Republican Ashley Hinson at 56.5% against Democrat Josh Turek at 43.5% on Kalshi, 57.5/42.5 on Polymarket. In mid-September it was 58/42.

Kalshi lists it three times and gets three answers. The main Categorical says Hinson 56.5%. A second Kalshi book, Iowa Senate winner? (Person), says 57.5%—and prices Turek at 44%, so that book sums to 101.5%. The Governor–Senate combo implies Hinson at 52% (36% Sand-and-Hinson plus 16% Republican sweep). Five and a half points of spread across three books on the same exchange, same question, same day.

Positioning has turned over. In mid-September Hinson's leg held three times Turek's open interest. Now Turek's holds the larger position, 1,324,333 against 1,109,259, and takes the larger share of a much bigger day: $56,783 to $50,103 on a book that turned $106,971, five times its September volume.

Below: the winner books, a margin ladder listed in only one direction, the Governor–Senate combo, and the four-state tossup book.

Hinson 56.5% on Kalshi, 57.5% on Polymarket; Turek 43.5% and 42.5%. One point apart, and Kalshi carries nearly sixteen times the volume ($106,971 to $6,837) and about seven times the open interest. With a month to go this is the turnover a live race draws.

Hinson and Turek priced directly. Price still favors Hinson by thirteen points, but both the day's money and the standing position now lean to Turek: $56,783 against $50,103 traded, and 1,324,333 against 1,109,259 of open interest.

Kalshi lists Iowa Senate margin rungs for the Democrat and no one else. Turek by 2+ prices 42%, 4+ at 20.5%, 6+ at 9.25%, and the ladder has finally traded: $2,626 today, nearly all of it on the 2+ rung. That rung sits a point and a half under Turek's 43.5% to win at all, which says the ladder is quoted loosely. There is still no Republican-side ladder, on the race the same exchange prices 56.5% Republican.

The combo book has changed its mind. In mid-September its modal outcome was a split ticket. Now a Democratic sweep leads: Rob Sand and Josh Turek at 45.5%, ahead of Sand and Ashley Hinson at 36% and a Republican sweep at 16%. It traded $481, so read it as a quote more than a price.

• The combo's lead change. Sand-and-Turek at 45.5% has passed the Sand-and-Hinson split ticket at 36%. The book is thin, $481, but it implies Hinson at 52%, well under the main book.
• Five and a half points across three Kalshi books. 52%, 56.5% and 57.5% on one question. Any read that quotes "the Kalshi price" for Iowa is picking one of three.
• Position and flow now both lean Turek. 1,324,333 of open interest against Hinson's 1,109,259, and $56,783 of the day against $50,103. In September the standing position ran three to one the other way.
• A one-directional margin ladder. Three Democrat rungs, no Republican rungs. If Kalshi lists the other side, that is a signal the exchange sees demand for pricing a Hinson margin.
• Governor versus Senate. Sand is 86.5% for the Governor's mansion while Turek is 43.5% for the Senate, a forty-three point spread between two Iowa Democrats on the same ballot.
• The tossup combo. Democratic sweep 28.5%, Republican sweep 17.5%, and the leading partial outcomes all exclude Iowa: it is priced as the hardest of the four for Democrats.
• Election day is November 3.

The Governor's race runs the other way, and by more than it did. Democrat Rob Sand prices 86.5% against Republican Zach Lahn at 14.5%, up from 78% in mid-September, on $8,313 a day. Polymarket is close behind at 88.5/11. So the same Iowa electorate is priced 86.5% Democratic at the top of the ticket and 56.5% Republican one line down—a forty-three point spread, and the reason the split ticket is still priced at 36%.

The Governor book's two legs still hold nearly identical open interest, 298,755 and 279,026, despite the six-to-one price gap, and the cheaper leg took more of the day: $5,406 on Lahn to $2,908 on Sand.

Two books that price Iowa against something other than itself.

The second Kalshi Iowa book (Iowa Senate winner? (Person)) has Hinson at 57.5% and Turek at 44%, summing to 101.5%, on $108 of volume against the main book's $106,971. Two books on one exchange, a point apart on the favorite.

The four-state tossup combo prices which of Texas, Alaska, Iowa and Ohio the Democrats take. A Democratic sweep is 28.5%, a Republican sweep 17.5%, and the next outcomes are Texas, Alaska and Ohio at 16.5% and Texas and Alaska at 11%: the leading partial outcomes all leave Iowa out. The market prices Iowa as the last of the four to flip, on $938 of volume.