Ohio's Senate special is the race where the 2026 map's two biggest forces collide head-on: a national environment leaning hard against the president's party, and a state that has voted Republican by eight to 11 points in three straight presidential elections. For 11 days the market has been arguing with itself about which force wins. Kalshi's contract on the race has flipped favorites twice since August 7, tripled its lifetime volume to about 2.1 million contracts, and just posted the heaviest 24 hours of trading in its history (roughly 402,000 contracts), with former Sen. Sherrod Brown coming out the other side at 51/52 cents against appointed Sen. Jon Husted at 48/49. The polls, meanwhile, are arguing with each other: the last three public surveys all have Brown up 4 to 8 points, and the Pollsmax polling average still reads Husted +1.8. This page walks through who moved the price, session by session, and what our price-blind AI panel, which called this race a coin flip before any of it happened, says about which side to believe.
The Quick Answer
Kalshi now pays 51/52 cents on Sherrod Brown against 48/49 on Jon Husted, on a one-cent spread, after the contract's heaviest trading day yet. The polls point in opposite directions: Fox News (Aug 6-10) has Brown +8 and Wedgewood (Aug 11-13) has him +4, while the Pollsmax average across its 16-poll set still shows Husted +1.8. The market has landed almost exactly on our seven-model panel's August 7 verdict of 49.9% for Brown, a true coin flip. The session-by-session money flow, the poll fight, and every seat's number are below.
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New to event markets? How to bet sports on Kalshi covers the exchange mechanics; this page is the Ohio layer. Prices on this page refresh on our standard market-pulse cycle, with the as-of stamp below as the evidence.
The Board
| Candidate | Party | Kalshi (Aug 18) | Change since Aug 7 | AI Blend (frozen Aug 7) |
|---|---|---|---|---|
| Sherrod Brown | Democratic | 51/52¢ | −1¢ | 49.9% |
| Jon Husted | Republican | 48/49¢ | +1¢ | 50.1% |
Prices are live bid/ask fetched August 18, 2026, 11:06 UTC; the blend is frozen at its August 7 generation date. These are model estimates, not predictions of fact and not financial advice.
More live boards from the same panel: North Carolina Senate · Maine Senate · the full 2026 Senate hub
The panel has scored Ohio's Midwest neighbors too, and they bracket this board from both ends of the certainty scale: the Iowa Senate model verdict (Hinson vs. Turek, another open-seat board), the Michigan Senate model verdict (El-Sayed vs. Rogers, re-scored after that state's primary), and the Minnesota Senate model verdict (an open DFL seat priced like a near-certainty that the panel reads as merely strong). Next to any of them, Ohio is the map's one true coin flip, and now it trades like one.
The case for each side of the Ohio (OH) Senate race, priced on Kalshi: Why Jon Husted (R) Will Win the Ohio Senate Race · Why Sherrod Brown (D) Will Win the Ohio Senate Race
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The Market
The contract (SENATEOHS-26) settles on which candidate is elected in the November 3, 2026 special election for the final two years of the term JD Vance vacated to become Vice President. Husted was appointed to the seat in January 2025; Brown, who held Ohio's other Senate seat for three terms before losing it in 2024, won the Democratic primary easily. Cook and Sabato both rate the race Tossup, and it is the only R-held special on either rater's competitive list. The winner defends the seat again in 2028.
The book has changed shape completely since our panel ran. Through August 7 the market had matched about 650,000 contracts lifetime; it now sits near 2.1 million, meaning two-thirds of everything ever traded on this race printed in the last 11 days. Volume still tilts hard toward the Husted contract (about 1.33 million contracts to the Brown contract's 772,000) while price now tilts to Brown. Kalshi is a CFTC-regulated event-contract exchange; 18+, availability varies by state as of August 2026.
Eleven Days, Two Flips
Here is the part the price alone doesn't show. When our panel ran on August 7, Brown was the favorite at 52.5 cents. Within two days the market threw that out: on August 8-9, in the contract's first genuinely heavy trading (about 322,000 contracts on Aug 9 alone), Husted ran to 52 cents and Brown fell to 48-49. Husted held that narrow lead through August 12, and the August 13 session traded to a dead heat, both contracts closing at 51 cents on their separate books. Then the mid-August polling wave landed and the market flipped back: Brown retook the lead on August 14 and has closed between 51 and 53 cents every session since. Today's price isn't the market agreeing with its August 7 self; it's the market returning to the same place by a much more violent road.
The four heaviest sessions in the contract's life tell the story in order:
| Session (UTC) | Contracts traded | Husted last | Brown last |
|---|---|---|---|
| August 9 | ~322,000 | 52¢ | 49¢ |
| August 13 | ~277,000 | 51¢ | 51¢ |
| August 15 | ~281,000 | 48¢ | 53¢ |
| Last 24 Hours (To Aug 18, 11:06 UTC) | ~402,000 | 49¢ | 52¢ |
Closing last trades per Kalshi's daily candles; the two contracts trade on separate order books, so a day's last prices needn't sum to exactly 100 cents. The final row is a rolling 24-hour window rather than a calendar session, shown because it is the largest 24-hour tape the contract has ever printed.
The row worth staring at is August 13. That was the day the Wedgewood poll hit, and the Husted contract absorbed 267,000 of the session's roughly 277,000 contracts, printing an intraday low of 44 cents (a seven-point range) before buyers walked it all the way back to a 51-cent close. Someone treated the new poll as a selling event, and someone else treated the sold-off price as a gift. The next two heavy sessions settled it: August 15 closed Husted at 48, and the last 24 hours (the biggest tape yet, with three-quarters of it in the Husted contract) closed him at 49 with Brown printing 52. Since the poll wave began, every burst of size has closed Brown above where he started that session. That is what "which side did the money move to" looks like on an exchange: not who traded more, but where the price closed after they did.
What The Polls Say Now — And Why They Disagree
The volume story only makes sense against the polling story, because the polls stopped agreeing with each other in mid-August. Our panel's August 7 card carried an eleven-poll feed whose newest entry was a June 28 NYT/Siena read; every public survey fielded since that one shows Brown ahead:
- Fox News (Beacon Research/Shaw & Co., Aug 6-10, 1,008 Registered Voters): Brown 53, Husted 45. The same bipartisan pollster pair had this race Brown 53-45 in early June too — Fox's series has now shown Brown +8 twice in a row.
- Wedgewood Polls (Aug 11-13, 800 Likely Voters): Brown 48, Husted 44. The crosstab that traders chewed on: 9 percent of Ohioans who voted for Trump in 2024 say they're undecided in the Senate race, nearly double the undecided rate in the governor's race, while Husted holds 85 percent of the 2024 Trump coalition and Brown takes 94 percent of Harris voters.
- Tulchin Research (D) (Aug 4): Brown 47, Husted 43.
Set against that: the Pollsmax average still reads Husted +1.8 (47.1 to 45.3 across its 16-poll set), because the aggregate still carries the earlier nonpartisan set that leaned the other way: on our panel's August 7 card, NYT/Siena had Husted +3, Bowling Green/YouGov +3, Echelon +6, and Emerson +2.5, and the card's own eleven-poll raw average was Husted +0.4. Nothing in that older set has been contradicted by a pollster of the same class; the new Brown leads come from Fox's bipartisan pair, a lightly-tracked house, and a Democratic firm. So the disagreement is not noise, it's a real quality-versus-recency fight: believe the freshest numbers and Brown is up mid-single digits; weight the graded nonpartisan record and the race still leans a point or two to Husted. The market's 51/52 on Brown is, almost literally, the midpoint of that fight.
If that tension sounds familiar, it should: it is the exact argument that produced the biggest swing inside our panel 11 days before the polls forced it on the market.
How The Panel Read It
On August 7, price-blind, every seat weighed the same three blocks and disagreed only on the weights. The case for Brown is the environment:
"The strongest driver is the national environment: a Republican president near 38/59 approval and a Democratic generic-ballot lead around 5-6 points imply a meaningful anti-incumbent midterm wind, and Ohio's special election should be exposed to that." (ChatGPT)
The case for Husted is the polling composition and the state's recent habit of under-polling Republicans:
"Ohio-specific polling error: Ryan polled near-even and lost by 6.1 in 2022; Brown polled ahead and lost by 3.6 in 2024." (Claude Opus)
"A tied race in Ohio historically tilts Republican because late-deciding non-college and rural voters break R." (Kimi K3)
And the case for calling it a coin flip is that both arguments are real:
"Brown lost 2024 by 3.6 in a roughly R+2 national year; shifting to today's D+5-6 generic ballot and Trump at net -20 implies a small Brown edge." (Claude Fable)
The structural facts behind those quotes cut both ways with equal force. Ohio has voted Republican by 8 to 11 points in every presidential election since 2016, and Republicans hold every statewide executive office. But Brown's 2024 loss came by 3.6 points while Trump carried the state by roughly 11 (a seven-point overperformance of his party's baseline), and 2026 has no Trump on the ballot. The national card at generation time read: generic ballot D+5 to +6, presidential approval near 38/59, and the postwar ledger showing the president's party losing ground in 18 of 20 midterms.
Every Seat's Number
Both rounds shown; the headline blend averages the revised column. These numbers were generated August 7 and are deliberately frozen: the point of a graded panel is that it doesn't get to revise after watching the market. On a phone this table scrolls sideways.
| Seat | Round 1: Brown wins | After revision |
|---|---|---|
| Claude Fable | 55% | 53% |
| Claude Opus | 40% | 48% |
| Claude Sonnet | 55% | 52% |
| ChatGPT | 54% | 53% |
| Gemini 3.1 Pro | 61% | 42% |
| Grok 4.5 | 54% | 54% |
| Kimi K3 | 46% | 47% |
Every seat on this panel is graded against real market settlements — records to date: GPT 83% on 2,013 graded calls · Claude Fable 84% on 334 graded calls · Claude Opus 85% on 385 graded calls · Claude Sonnet 83% on 366 graded calls · Gemini 85% on 2,062 graded calls · Grok 80% on 1,888 graded calls · Kimi 83% on 2,099 graded calls. Recomputed daily; the full scoreboard is public.
Model estimates generated August 7, 2026, price-blind from live fetched data. These are model estimates, not predictions of fact and not financial or trading advice. Models are frequently wrong; the market price reflects real traders' money. Kalshi is a CFTC-regulated event-contract exchange; 18+, availability varies by state.
Every number in this piece lands in our backtest ledger the day it is generated and gets graded against the certified result on the public model verdict scoreboard.
Where The Panel Changed Its Mind
This board produced its sprint's biggest single revision, and the argument that caused it is the same one the polls are now having in public. Gemini 3.1 Pro opened at 61% for Brown on the strength of the national environment and Brown's 2024 overperformance. After reading the room it printed 42%, writing that "high-quality nonpartisan polls (NYT/Siena) show Husted leading" and that "Ohio polling consistently understated Republicans in 2022 and 2024, implying Husted's true lead is larger." A nineteen-point swing on one argument about whose polls to believe: the quality-versus-recency fight, 11 days early.
The traffic ran both directions. Claude Opus, the round-one low at 40%, came back at 48% after crediting the environment case it had underweighted. And Grok 4.5 held its 54% both rounds, writing that the referendum dynamic of an R-held special in a minus-20 approval environment was still the heaviest single weight. Cross-seat spread fell from 21 points to 12, and the blend moved from 52.1% to 49.9%: a revision round that moved the panel toward the underdog side of the market. Eleven days and two flips later, the market has come back to within 1.6 points of that number.
What Would Change The Panel's Mind
- A Gold-Standard Nonpartisan Poll. This catalyst has half-fired: the mid-August wave brought Fox's bipartisan +8 and Wedgewood's +4, but not the NYT/Siena- or Emerson-class read the panel said would move every seat. Whichever way the next one points, it settles the quality-versus-recency fight directly.
- A Debate. Both a first-term appointee and a comeback candidate have something to prove on a stage; either stumbling is the kind of discrete event the seats' toss-up math would reprice on.
- Q3 Fundraising Reports (October). The money race is the cleanest measurable proxy for enthusiasm in a race this tight.
- Movement In The National Numbers. Every seat conditioned its estimate on D+5-6 generic and minus-20 approval. If either moves three points in either direction, this race's number moves with it.
Settlement Timeline
- November 3, 2026 — election day; the contract settles on the certified winner.
- September-October 2026 — debate scheduling and the post-Labor Day polling wave, the two known catalyst windows.
- 2028 — the winner defends the seat again for the full term, a separate future market.
- This page re-scores when the story moves; prices above are as of August 18, 2026, 11:06 UTC.
How To Read These Prices
- Eligibility. Kalshi is a CFTC-regulated event-contract exchange, not a sportsbook. 18+, availability varies by state as of August 2026. Election event contracts are legal to trade there.
- Liquidity. About 2.1 million contracts matched, most of it in the last 11 days, on a one-cent spread. This is real two-sided liquidity, not a wide quote, and the busiest 2026 general-election race market in our daily volume scan.
- The Panel Is Not The Market. The blend is the simple mean of seven revised model estimates, disclosed in full above; the market is real traders' money. On this board they sit 1.6 points apart, which is agreement in any practical sense.
- Not Advice. These are model estimates, not predictions of fact and not financial advice.
OddsShopper's odds screen and free expert picks cover the sports slate rather than election futures, and the Ohio race itself lives on Kalshi, but the discipline of comparing a price to an independent estimate is the same, and every number on this page lands in our publicly graded Model Verdict ledger.
More on this: 2026 Senate Races: Every Kalshi Board We Track · 2026 Senate Election Odds: One Race Splits The Machines · Markey vs Moulton: 'I'll Vote for the Old Man' Voters Say · Sununu vs Brown: Trump's Pick Skips the Last Debate · Ohio Governor Odds 2026: Acton's 252K Kalshi Day
The Bottom Line
Eleven days ago the market paid Brown a small premium and our panel refused to, calling the race 49.9% on a tied-but-Husted-leaning polling record set against a historically hostile national environment. The market then tried both answers (Husted 52 on August 9, Brown 53 on August 15), and the heaviest trading in the contract's life has now walked it back to within a point and a half of the panel's coin flip. So the open question is no longer market-versus-panel; it's the poll average against the last three polls, Husted +1.8 on the aggregate against Brown +4 to +8 on everything fielded since August began. Watch one thing from here: the next nonpartisan, gold-standard poll. The 44-cent print that got bought back on August 13 says traders won't settle this fight on a partisan or lightly-graded survey, and every seat on our panel said a NYT/Siena-class read would move its number. Until it lands, this is what a Tossup rating looks like when two million contracts put a price on it. The certified result grades every number above in public, alongside the North Carolina and Maine boards from the same panel.
Verdicts generated August 7, 2026, price-blind. Prices as of August 18, 2026, 11:06 UTC. Panel: seven of the panel's eight seats ran this board (ChatGPT, Claude Fable, Claude Opus, Claude Sonnet, Gemini 3.1 Pro, Grok 4.5, Kimi K3), each revising in an anonymized cross-read; the blend is the simple mean of the seven revised numbers. Strictly analytical, no advocacy: data and probabilities only. These are model estimates, not predictions of fact and not financial advice.
Prices on this page are Kalshi's book. If you also trade on Polymarket, code OS4 gets new users a $50 trading bonus on a $10 deposit — affiliate link; terms as stated by Polymarket; 18+, availability varies by state.
