On Monday afternoon, August 31, the entertainment press was writing up Onslaught as a hit with critics: 80% Fresh on 20 reviews in ComicBookMovie's roundup, 76% on 25 at MovieWeb, an embedded early count of 83% on a dozen. By Wednesday evening ScreenRant had it at 73%. At 7:45 PM ET on Thursday, September 3, the night before the A24 action thriller opens wide, the Rotten Tomatoes page reads 59% on 69 reviews. Below 60 is Rotten. The film lost its Fresh badge before it opens wide, and the most precise record of the fall is a Kalshi board, ticker KXRT-ONS, where the contract asking whether the final score lands above 60 was bought at 95 cents at noon and at 25 cents four and a half hours later.
I wrote up the same kind of board for Coyote vs. Acme, which settled this past Monday, August 31, on a rounding line: a raw 95.50 that printed as 96 over an Above 95 strike. This board is the opposite animal: a score in free fall, an exchange that listed new strikes twice in one day to keep up with it, and a strike ladder that now says the most likely final print, the score displayed at settlement, is a 56 or a 57. The arithmetic of what it takes to stop the slide, and what a trader is really buying between the 55 and 60 strikes, follows.
These are market prices and model estimates, not predictions of fact and not financial advice. Kalshi is a CFTC-regulated event-contract exchange. Kalshi requires users to be 18+ under its own platform policy, and availability varies by state. Rotten Tomatoes has not endorsed these markets; references to Rotten Tomatoes here are descriptive only.
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The Quick Answer
Kalshi's Onslaught market, KXRT-ONS, settles on the film's Rotten Tomatoes Tomatometer at 10:00 AM ET on Monday, September 7. With the score at 59% on 69 reviews on Thursday night, the "Above 55" contract was quoted at 74 cents bid against 75 ask, "Above 60" at 25 against 26, and a brand-new "Above 57" strike, listed at 7:00 PM ET, at 42 against 45. Read as a distribution, the ladder puts about a one-in-three chance on a final of exactly 56 or 57 (a split that rests on the hour-old, 185-contract Above 57 rung), a coin flip on anything from 56 to 60 priced off the deep 55 and 60 strikes, and roughly one-in-four on a print of 61 or better, the number the Above 60 contract pays on. The strike-by-strike table, and the review math behind those odds, is below.
How The Score Fell: From 80% To 59% Since Monday
Director Adam Wingard and writer Simon Barrett, the pair behind The Guest and You're Next, carry a genre following, and that following is why the first 20 reviews of their Carpenter-style siege, with Adria Arjona's Army sniper defending her trailer park from three escaped super soldiers alongside Dan Stevens, Eric Wareheim, Reginald VelJohnson and Michael Biehn, came in at 80% positive. A24 opens it wide on Friday, September 4, rated R and 92 minutes long, and 80% was never the pool's true center.
MovieWeb's August 31 roundup quoted IndieWire on action with "a satisfying crunch" and SlashFilm calling it "the single greatest John Carpenter movie that John Carpenter never made," and reported 76% on 25 reviews at 1:42 PM ET. ComicBookMovie's piece the same afternoon counted 80% on 20, a snapshot taken earlier than its 4:08 PM publish time since a review count cannot shrink, with an embedded post showing 83% on 12. By CBR's write-up on Tuesday it was 75%, and ScreenRant had 73% at 6:00 PM ET Wednesday, noting that some critics found it lacking in tension and unpleasant to watch. The trades were not unanimous either: Variety's headline called it a "fun but scattered military slasher," and Metacritic, which scores on a 0-to-100 scale rather than fresh-or-rotten and on a smaller pool of 19 critics, sits at 60, its "mixed or average" band.
Thursday erased the margin. Between ScreenRant's 73% on Wednesday evening and my 7:45 PM ET pull of the Rotten Tomatoes page on Thursday, the score dropped 14 points to 59% on 69 reviews. Hold the two dated counts side by side. MovieWeb's 76% on 25 can only be 19 positive against 6 negative. Thursday's 59% on 69 can only be 41 positive against 28 negative if the site rounds to the nearest whole number, which the Coyote vs. Acme settlement showed it does when a raw 95.50 printed as 96; the 41-against-28 split holds under truncation too, and the two-review distance to 61 below is the one figure that depends on rounding. Subtract one from the other and the 44 reviews that arrived between Monday lunchtime and Thursday night ran 22 positive, 22 negative. Exactly half. A pool that opened at four-in-five positive has spent the week since Monday absorbing reviews that split down the middle, and an even split dilutes an 80 toward a 50 with no drama required.
The Tape: Noon Buyers At 95 Cents, A Ladder Rebuilt Twice
The market did not see it coming, and the trade tape shows how late the information arrived. Each contract on KXRT-ONS asks whether the Tomatometer will be above its strike at settlement, paying $1 for Yes and nothing for No; if cents-to-probability is new to you, our Kalshi odds explainer covers the conversion. At 11:58 AM ET Thursday, a buyer paid 95 cents for 4,984 contracts of Above 60, a position that the score would finish 61 or better, priced at roughly 19-to-1 confidence. Above 65 had been bought at 73 cents in size at 11:14 PM Wednesday and again at 71 cents at 9:18 AM and 10:38 AM Thursday, 3,500 contracts across the two morning prints. At noon, the exchange itself added five new one-point strikes, Above 66 through Above 69 plus Above 71, which gave traders finer resolution around a score the market had parked in the high 60s: Above 65 at 71 cents that morning, Above 70 in the low 20s by noon.
Those five rungs lived about four hours. In the 1:00 PM ET hour, Above 65 slid from 70 to 41 on 1,987 contracts, Above 70 fell from 24 to 6, and a seller hit Above 55 for 5,176 contracts at 94 cents at 1:29 PM, the largest single print on that strike all day. The 4:00 PM hour was the crash: Above 60 traded 108 times for 11,052 contracts, from a high of 86 cents to a low of 22, and Above 65 traded 146 times for 10,363 contracts, from 37 cents down to 2. The noon-listed rungs went with them; the five noon rungs turned over 28,350 contracts between them by the evening pull, about 24,000 contracts of open interest still sit on those strikes tonight, and every one of them shows a zero bid, with Above 66 the only one still asking more than a penny. Then, at 7:00 PM ET, the exchange listed two more strikes, Above 57 and Above 62, this time bracketing the range the collapse had left behind. A ladder built at noon for a Fresh movie was rebuilt at dinner for a Rotten one, which is as sharp an illustration of what actually moves a prediction market as I have seen: new reviews, arriving in a pool small enough that each one counts.
The crash hour did not only sell. In the 4:00 PM hour Above 60 traded 7,752 contracts to buyers who crossed the spread against 3,299 to sellers who did, so buyers were leaning into the slide the whole way down, and the biggest of them took 5,259 contracts at 25 cents at 4:34 PM ET. Somebody looked at a strike the tape had just repriced from 86 cents to 22 and paid $1,315 for the right to collect $5,259 if the weekend's reviews pull it back to 61. Whether that is a good trade depends on the review count, and the review count has a number on it.
The Board: Every Contested Strike On KXRT-ONS
The ladder runs 17 strikes deep, from Above 45 to Above 90, but the top ten are dead: everything from Above 66 up shows a zero bid against a penny or a nickel ask, a displayed market with nothing behind it, and Above 65 itself is 2 bid against 3. Above 45, at 97 bid against a full dollar, is the floor. The seven rows that follow, pulled from the exchange at 7:42 PM ET on Thursday, September 3, are the contest plus one marker: Above 70 is already dead, but it carries the day's third-largest volume, so it stays on the board to show how far the collapse ran. "Cost to buy" is the ask, the price a buyer actually pays; the bid is what a seller gets.
The contested strikes as pulled at 7:42 PM ET Thursday; the Above 57 and Above 62 rungs were less than an hour old.
| Strike | Bid / Cost To Buy | Last Trade | 24h Volume (contracts) | Open Interest (contracts) |
|---|---|---|---|---|
| Above 50 | 94¢ / 97¢ | 90¢ | 10,614 | 13,891 |
| Above 55 | 74¢ / 75¢ | 73¢ | 14,069 | 29,176 |
| Above 57 | 42¢ / 45¢ | 45¢ | 185 | 157 |
| Above 60 | 25¢ / 26¢ | 25¢ | 21,317 | 50,003 |
| Above 62 | 7¢ / 11¢ | none yet | 0 | 0 |
| Above 65 | 2¢ / 3¢ | 2¢ | 29,146 | 38,481 |
| Above 70 | 0¢ / 1¢ | 1¢ | 18,152 | 32,985 |
Prices as pulled at 7:42 PM ET on Thursday, September 3, 2026. Above 57 and Above 62 opened for trading at 7:00 PM ET the same evening; Above 62 had not traded at the pull. The 90-cent last trade on Above 50 was the tail of a single 2,374-contract sell order at 7:34 PM that mostly cleared between 94 and 96 cents.
The row to stare at is Above 60, and not only because it carries the most open interest on the board, 50,003 contracts still held by traders. The gap between its bid and ask is one cent, 25 against 26, on a strike that traded 21,317 contracts in 24 hours; the market has a firm opinion here, and the opinion is that a print of 61 or better, the number Above 60 needs, is roughly a one-in-four shot. Contrast the two strikes the exchange added at 7:00 PM. Above 57 is priced at 42 against 45 on 185 contracts of total volume, thin enough that a few hundred contracts would move it, and Above 62 has never traded at all; its 7-to-11 quote is a displayed opinion, not a market. Read the midpoints, halfway between bid and ask, down the ladder and the shape falls out: about 96 for Above 50, 74.5 for Above 55, 43.5 for Above 57, 25.5 for Above 60, 9 for Above 62, 2.5 for Above 65, under 1 for Above 70. Difference each rung from the one above it and you get the market's probability for each band of final scores. The fattest band is 56-to-57 at about 31 points, then 51-to-55 at 21, then 58-to-60 at 18. Add the two bands from 56 to 60 and the market has roughly even odds on the film settling anywhere from 56 to 60, which is to say Rotten but close. Treat the 57 and 62 figures as soft, given how little sits behind them; the 55 and 60 rungs are where real money has spoken.
The Arithmetic Of The Next Review
The ladder is anchored to a raw score of 59.42, which is what 41 of 69 works out to before rounding. The Coyote vs. Acme settlement taught me two things that carry straight over: Rotten Tomatoes rounds the half-point up, and Kalshi's "above" is strict, so a settlement print of exactly 60 resolves Above 60 as No. Put those together and each strike has a plain review count attached to it.
Above 60 needs a print of 61. The raw score has to reach 60.5, and from 41 of 69 that takes two straight positive reviews with nothing negative beside them: 43 of 71 is 60.56, which displays as 61. Two reviews. The contract that was bought at 95 cents at noon and sits at 25 tonight is, at this instant, two positive notices from paying.
Above 57 needs a print of 58. Three straight negatives kill it: 41 of 72 is 56.94, which displays as 57, and a 57 settles Above 57 as No.
Above 55 needs a print of 56. Five straight negatives with no positives break it: 41 of 74 is 55.41, a 55, and the strike the market prices at three-in-four goes to zero.
Those single-direction runs are the edges, and they are the wrong picture of how a review pool actually moves. Pools this size move by composition, the lesson the Coyote board left me with, and the composition question here has a number on it. Suppose 30 more reviews land before Monday's snapshot, a modest opening-weekend wave for a wide release. Above 60 pays only if 19 of them are positive, about five in eight; Above 57 needs 16; Above 55 survives at 14, just under half. Push the wave to 60 reviews and the counts become 38, 34 and 31, so the 57 and 60 bars barely move, about 57% and 63%, while the Above 55 bar crosses 50% to about 52%, which is the whole question for that strike. The table puts the three strikes side by side.
| Strike | Score it needs Monday | Straight run that decides it now | Positives needed in the next 30 reviews | In the next 60 |
|---|---|---|---|---|
| Above 55 | 56 or higher | Five negatives in a row break it | 14 of 30 (47%) | 31 of 60 (52%) |
| Above 57 | 58 or higher | Three negatives in a row break it | 16 of 30 (53%) | 34 of 60 (57%) |
| Above 60 | 61 or higher | Two positives in a row clear it | 19 of 30 (63%) | 38 of 60 (63%) |
Arithmetic from 41 positive of 69 reviews, the split implied by 59% on Thursday night, with Rotten Tomatoes rounding to the nearest whole number.
The middle row is the one the exchange added at dinner, and its bar sits almost exactly where the pool has been running. The 55 strike and the 60 strike, in other words, bracket one question: does the weekend's crowd of reviewers run better than about half positive, or better than about five-in-eight? The last 44 reviews ran exactly half. Feed that same clip forward and 30 more reviews land the score at 56.6, a 57, which pays Above 55 and buries Above 57 and Above 60; 60 more reviews at the same clip land it at 55.0, a 55, and Above 55 loses on the tie. The market's fattest band is 56-to-57 because the market is pricing the recent clip continuing, with a little room on either side.
The counter-argument is the shape of this pool itself. The first 20 reviews ran 80% positive and the 44 after MovieWeb's count ran 50%, a 30-point deterioration inside one film's page in three days. My read, and it is a read rather than a count, is that the early notices came from outlets predisposed to a Carpenter homage, and the wave that follows a wide release, filled in by regional and general-audience critics, tends to run cooler. That reading says half positive is the ceiling, not the floor, and it is the reading that pushed Above 55 from 99 cents at 10:00 AM Thursday to a 65-cent low in the 4:00 PM hour before it settled back to a 73-cent last print and a 74-to-75 quote. The other side of the argument is smaller but not nothing: at 41 of 69, the film is two reviews from 61, the pool is still small enough for a single good afternoon to matter, and the 5,259-contract buyer at 25 cents was taking the view that a Carpenter-throwback action movie with a Hollywood Reporter review calling it "gloriously crafted if narratively undercooked" behind it will find its audience among the critics who file over the weekend. At 25 cents, a $100 stake in that view turns into about $400 if the print reaches 61 and nothing if it does not, before Kalshi's fee of about a penny or two per contract at that price. The reader who wants to take either side should re-run the two-review and five-review arithmetic against whatever count the page shows when they look, because 69 will not be the number for long.
What Monday At 10:00 AM ET Actually Settles
The rules text on the market is short: "If Onslaught has a Tomatometer score of above 45 on Sep 7, 2026 at 10:00 AM ET, then the market resolves to Yes," with the strike number swapped in for each rung. The secondary rules add the clauses that decide everything here. The Tomatometer score must be above the strike value to resolve Yes; Kalshi's own example is that a score of 75 resolves "Above 75" as No. The market is determined the Monday after wide release at 10:00 AM ET, as a single snapshot. And the Fresh and Certified Fresh subtitles are "for illustrative purposes only," which matters on a board whose whole story is a badge that came off: the market does not care whether the film is called Rotten, only whether the number on the screen at 10:00 AM Monday clears each strike.
That snapshot design is why the count of incoming reviews, and how they split, decides this board. Every notice that posts before Monday morning counts in full, and a notice that posts at 10:01 AM changes nothing. We wrote up the full mechanics, including a case where a score landed exactly on a strike, 85 at the snapshot, and Above 85 resolved No because 85 is not above 85, in the Kalshi Rotten Tomatoes markets explainer, and the broader machinery is in how Kalshi settlement works. For readers newer to event contracts, what the price means covers the caveats and how prediction markets work covers the basics; the settled Coyote vs. Acme board is the worked example of this exact market family grading every claim at the snapshot.
- Coyote Vs. Acme Rotten Tomatoes: 96 Held. The Margin Was Zero
- Kalshi Rotten Tomatoes Markets: How Contracts Settle
- How Kalshi Settlement Works
- Kalshi Fees Explained
- What Actually Moves A Prediction Market
The Read
Strip the badge off and the board is asking one question in two prices: how positive is the weekend wave of reviews going to be? Above 55 at 74.5 says three-in-four that it runs better than about half positive; Above 60 at 25.5 says one-in-four that it runs better than about five-in-eight. The last four days ran exactly half, and the market's modal outcome, a 56 or a 57, is that clip carried forward. The part I keep coming back to is the asymmetry in how each side of that gap breaks: Above 60 is two positive reviews from paying but needs the whole wave to run a dozen points warmer than the pool has run since Monday, while Above 55 survives an evenly split weekend only if the wave stays small: 30 more reviews at the recent clip print a 57 and it pays, 60 more at the same clip print a 55 and it loses on the tie. Its enemy is the size of the wave as much as the tone. The 25-cent buyer at 4:34 PM is not wrong that two reviews is a short distance. The tape's answer is that the distance keeps growing with every review that lands, and lately every second one has landed on the wrong side.
Coyote vs. Acme settled on Monday, August 31 on a raw 95.50 that rounded up, with its decisive strike, Above 95, paying by zero reviews to spare. Onslaught will settle next Monday on a number that moved 14 points in a little over a day, and this page will be graded against it. You can follow how these boards grade out, across politics, sports and entertainment, when you browse every live market board on the prediction markets hub.
