On 2 September 2026 The Block reported that prediction market volume had fallen for the first time in a year, and the August figures in that story carry a sentence worth reading twice. Kalshi recorded 37.17 billion dollars, while, in the words of reporter Timmy Shen, "Polymarket and its U.S. platform saw a combined $8.16 billion". The wording is careful and correct. The brand does run two venues, and the figure is the sum of both.
That sum is the most widely repeated description of the company, and it is the one thing about the company that no rulebook governs. One half of it comes from a Panamanian company whose trades settle on a public blockchain and whose disputes are decided by a token holder vote. The other half comes from a Delaware exchange that files with a federal regulator, clears through a registered clearing house and has to publish its daily numbers because a regulation says so. Both halves are honest about themselves. Neither of them is visible in the number that travels.
Where the regulated half of the brand legally begins
The Commodity Futures Trading Commission designated QCX LLC as a contract market on 9 July 2025 under Sections 5 and 6(a) of the Commodity Exchange Act, 7 U.S.C. ยงยง 7 and 8(a). The Commission's own filing page for that designation adds the detail that makes the brand confusing: QCX LLC now operates under the assumed name Polymarket US.
The first order came with a restriction. As recited in the Amended Order of Designation issued by the Commodity Futures Trading Commission, the exchange "may not permit any futures commission merchant to intermediate any transactions or carry accounts for customers" unless the order were amended to allow it. The exchange petitioned to remove that clause in submissions dated 14 August 2025 through 24 November 2025, and the Commission vacated it. Polymarket announced the approval on 25 November 2025, with founder Shayne Coplan describing it as approval to operate in a way that reflects what the U.S. regulatory framework demands.
The same order records what the exchange undertook in exchange. Reporting under part 16 of the Commission's regulations would be delegated to a regulatory service provider, and intermediated trading would not begin until that provider had completed testing with the Commission's Division of Data. This is the practical difference between the two halves of the brand, and it has nothing to do with which one is bigger. One of them exists because of a document that can be read line by line, and every promise inside it has an addressee.
The other half is a Panamanian company with its own product line
The international platform is operated by Adventure One QSS Inc., the company named in the footer of Polymarket's own terms of use. The company's developer documentation describes the division plainly: in the words of the page What is Polymarket US, the international product is crypto based and runs on blockchain technology, while Polymarket US is fiat based and operates as a designated contract market and derivatives clearing organisation under CFTC oversight.
Since 3 September 2026 the two halves have not even offered the same asset class. Decrypt reporter Jose Antonio Lanz described the launch of Polymarket Perps on 4 September 2026, including leverage of up to 20x and a company FAQ that bars order placement from the United States, with American traders routed to Polymarket US instead. Reviewed on 15 September 2026, the platform's own public instruments endpoint listed 83 perpetual instruments: 40 crypto, 36 equity linked, four commodity and three index contracts, of which eleven allow the full 20x.
We are not against any of that existing. A leveraged derivatives venue for non-U.S. traders is a legitimate product and the geoblock is the company doing the right thing. The point is narrower and harder to argue with: a leveraged perpetual futures venue and a U.S. event contract exchange now sit on either side of one brand name, and the figure most often quoted about that brand adds them together.
Two machines for deciding who was right
On the international platform, resolution runs through the UMA Optimistic Oracle. As the company's Polymarket 101 page sets it out, a proposer submits an outcome with a bond, a challenge period follows, and a disputed market is decided by a vote of UMA token holders. The mechanism is public, and anyone can watch it work.
On Polymarket US the same job is done by the exchange. Its market resolution page says outcomes are determined from the sources named in each market's rules and that unlisted sources have no effect, with settlement processed by Polymarket Clearing and finality governed by the exchange rulebook. A trader who disagrees with a resolution is therefore in two completely different positions depending on which half of the brand they were using. On one side the recourse is a bonded dispute and a vote. On the other it is a rule filed with a regulator, an exchange with a compliance department and a self regulatory obligation.
Neither of those is obviously the better design, and we are not going to pretend otherwise. What is not defensible is a trader reaching the end of a contested market before discovering which of the two they were relying on.
Only one of the halves has to publish its numbers
The Polymarket US Rulebook dated 14 September 2026 contains Rule 5.10, headed Public Data, which commits the exchange to post pricing, current volume and open interest for all active contracts on each trading day, and to post anything else required by CFTC Regulation 16.01. That regulation is not a formality. Under 17 CFR 16.01, a reporting market records volume and open interest data for each trading session, and paragraph (e)(1) requires it to make that information "readily available to the news media and the general public without charge" no later than the following business day.
The international platform publishes open interest as well, through an exchange statistics endpoint whose documentation defines it as the one sided dollar notional taken from the most recent complete sample. The data exists on both sides. Its standing does not. On one side publication is an obligation owed to a regulator and written into a rulebook; on the other it is a product decision that can change with a release, and nobody outside the company gets a say. That distinction is exactly the one we drew in August about open interest, and it applies with more force when the two regimes share a logo.
Who is holding the money while a position is open
The international model is non custodial. Polymarket 101 states that assets stay in the user's own wallet, that the platform never takes possession of funds, and it carries a warning that losing the private key means losing access to the money. The trade off is explicit, and for many users it is the attraction.
Polymarket US is the mirror image. Its participant documentation describes account funding by debit card, bank transfer and wire, with identity verification, while the rulebook defines the clearing house as QC Clearing LLC, doing business as Polymarket Clearing, a Delaware limited liability company, and routes intermediated customers through futures commission merchants. Cash sits with a registered clearing organisation instead of in a wallet the user controls.
Directive 02 of our manifest asks that "fees, spreads, settlement sources, custody arrangements and conflicts of interest are stated in plain language on the surface where the trade happens". Custody is named in that sentence for a reason. It is the single fact that decides what happens to a balance when something goes wrong, and it is the fact that changes most completely between the two halves of this brand.
The company does explain the split, in the developer documentation
None of the above is hidden. Polymarket maintains two separate documentation sites, the international one carrying a banner that points readers to the U.S. documentation, and the U.S. one opening with a comparison of the two products. A visitor from the United States arriving at the international domain is steered to the U.S. app. The company is not pretending to be one thing.
The difficulty is where that explanation lives. A comparison card inside developer documentation reaches people building integrations. It does not reach the reader who saw a combined volume figure in a news story and downloaded whichever app the search result offered. Directive 02 puts the requirement on the surface where the trade happens, and a documentation site is not that surface.
There is a smaller sign of how far apart the halves have drifted. Reviewed on 15 September 2026, the U.S. documentation lists markets on the NFL, NBA, NHL, MLB, MLS, college basketball, tennis and golf, with politics, culture, finance and economics described as coming soon. The category that made the brand famous is, for now, on one side of the wall only. A reader who knows Polymarket for election markets and opens Polymarket US is meeting a different product, and the only place that is spelled out is a documentation page.
What a single volume line does to a comparison
The combined figure invites a comparison that does not hold. Set against Kalshi's 37.17 billion dollars for August 2026, the 8.16 billion attributed to Polymarket looks like one competitor against another. It is not. Kalshi is a single designated contract market under one set of core principles. The Polymarket figure is a regulated U.S. exchange plus an offshore venue, added together, with the split between them invisible in the number.
There is a second measurement problem stacked on top of the first, because volume in this category is reported in two incompatible units, notional and cash, which is why the same month can carry two defensible figures that differ by a multiple. We have written before about what happens when one product answers to several names, and this is the same failure running the other way: several products answering to one.
The fix is not for reporters to stop adding the numbers up. Data providers publish what venues give them. The entity that can end the ambiguity in an afternoon is the one that owns both halves.
Four things a two entity brand could publish this month
- Label every public figure with the entity that produced it. If a volume number covers two venues, say so in the same line, not in a footnote a data provider may drop.
- Put a one screen entity summary on both trading surfaces. Which company holds the funds, which rulebook applies, who decides the outcome, and which regulator, if any, can be complained to.
- Give the Rule 5.10 data a stable public address, and mark the international equivalent as voluntary where it is published, so a reader can see which of the two numbers carries an enforceable obligation behind it.
- State, at the point of promotion, when a product exists on one side only. Perpetual futures with 20x leverage are advertised under a brand name whose U.S. exchange cannot list them, and the traders most likely to be confused are the ones the geoblock catches.
None of these requires a regulator, a rule change or a competitor to move first. All four are things the company already knows and has written down somewhere.
A trader should not need a rulebook to know which side they are on
The interesting thing about this case is that the disclosure problem survived doing almost everything else right. Polymarket acquired a licensed exchange rather than arguing it did not need one, accepted the intermediation restriction in the 2025 order and then had it lifted through a documented petition, publishes a rulebook, geoblocks a leveraged product from a market where it is not permitted, and describes the two products side by side in its own documentation. That is a better record than the category average, and saying so costs us nothing.
What is still missing is the last link, the one that connects all that structure to the person placing the trade. Directive 05 asks that standards be set against the jurisdiction that regulates next rather than only the one that has not arrived yet. A brand that spans two jurisdictions is already living in that future, and the standard it will eventually be held to is simple enough to adopt early. Say which entity a number came from. Say which rulebook a market sits under. Say it where the money goes in.