Developing Kalshi Listed a Leveraged Stock-Index Perpetual This Morning. CME's Brief Arguing That Product Category Is Illegal Was Due Four Days Ago

The contract that went live on Kalshi this morning is called US500PERP. It has no expiry. It tracks the MerQube US Large Cap Index at a dollar a point, settles in cash, clears through Kalshi Klear, can be traded in slices as small as a ten-thousandth of a contract, and trips a position accountability review at $25 million. It trades Sunday evening through Friday afternoon — the same session CME runs for its equity-index futures, which is not a coincidence.

The CFTC classified it as an equity-index future on October 3.

CME Group's brief arguing that the CFTC cannot lawfully classify a perpetual contract as a future was due on October 2.

The sequence, in order

CME sued the CFTC and its chair, Michael Selig, on June 18 in the District of Columbia. The case is Chicago Mercantile Exch. Inc. v. Selig, No. 1:26-cv-02157, and it is not really about bitcoin. Its target is the May 29 order approving Kalshi's BTCPERP — an order that expressly rejected the argument that a perpetual cannot be a future merely because it never expires — and, more importantly, the policy statement issued alongside it, which lets a designated contract market self-certify a digital-commodity perpetual as a future and routes everything else to Commission review under Regulation 40.3.

CME's complaint is an Administrative Procedure Act complaint. The agency never engaged the comments filed in April 2025. It reversed a longstanding position without explaining itself — the same agency had taken the opposite view in its enforcement work against Binance and BitMEX. It adopted Kalshi's reasoning wholesale. And the procedural allegation that should bother anyone regardless of where they land on the merits: CME says the order issued one day after the application, against a review window that runs 45 to 90 days, with no opportunity for public comment.

The substantive claim is that a perpetual has no set future delivery, which is the defining feature of a future, and that what it actually consists of is an exchange of funding payments keyed to the value of a commodity, with price risk transferred and no ownership interest anywhere in it. Which is a swap. Terry Duffy had said the short version in public on June 4, alongside calling the products a disaster waiting to happen: "When there's two parties exchanging payments to each other, that's deemed a swap."

The CFTC's response was not conciliatory. A spokesperson called the suit frivolous and said CME had chosen lawfare over competition. Selig's defence was jurisdictional in the broadest sense: absent a regulated path onshore, the volume goes offshore. In early September the agency moved to dismiss — accounts differ on whether the filing landed on the 2nd or the 3rd — arguing first and loudest that CME has no standing, because it has shown no financial harm, because its own volume went up rather than down, and because nothing stops CME listing the identical contract. "This lawsuit is much ado about nothing," the filing says. The court's scheduling order gave CME until October 2 to oppose.

Then, on October 3, the agency extended the same classification into equities. Kalshi listed on the 6th.

Why the label is the entire argument

It would be easy to read this as a labelling dispute between two exchanges. It is a dispute about which rulebook governs tens of billions of dollars of flow, and the gap between the two is large.

If a perpetual is a swap, dealers have to register under 7 U.S.C. § 4d(a). The position falls under the Part 43 and Part 45 reporting regimes. Margin and collateral requirements get materially heavier. If it is a future, none of that attaches, and gains fall under Internal Revenue Code § 1256, which is the more favourable treatment. The same economic exposure, priced identically, costs a different amount to carry depending on which of two words a regulator writes down.

That is why CME is suing over a product it is free to list. The company that owns the incumbent equity-index franchise is not arguing that Kalshi should be kept out of its market. It is arguing that the door Kalshi walked through was opened unlawfully, and that if perpetuals are going to exist onshore they should exist with a swap's compliance load attached. Self-interested, obviously. Also the better reading of the statute, on the face of the text — "future delivery" is in the definition for a reason, and a contract with no delivery date is a strange thing to call a future.

One detail worth sitting with: this is not an S&P 500 product, whatever the headlines say. One outlet ran "CFTC Approves Kalshi S&P 500 Stock Index Perpetual Futures" above a story whose own body correctly identifies the reference as MerQube's US Large Cap Index. Kalshi built its exposure on a licensed third-party index instead of the benchmark it would obviously prefer. We cannot see the licensing file, so treat this as inference rather than fact: the index an American exchange would most want for a retail equity perpetual is already committed elsewhere, and MerQube is what you use when the front door is shut.

The strongest case that none of this matters

Here it is, and it is not a weak one. Financial contracts were $83.25 million of Kalshi's volume in the week ending October 4. Total volume that week was $18.37 billion. That is 0.45 per cent — after a 646 per cent weekly increase. Sixty-four per cent of the book, $11.82 billion, was exotics, which is to say multi-leg sports combos; the single largest market on the venue was a ten-leg NFL parlay that traded $117.16 million. One combo did more volume than the entire financials category. By that measure, writing about an index perpetual as though it were strategically significant is dressing up a press release.

We think the objection measures the wrong thing, and here is the test that would settle it. If this were a revenue play, Kalshi would be building where the money already is, and the company that spent 2026 launching crypto perpetuals in May, filing metals in July, filing equity indexes in August and now filing single-stock and ETF perpetuals on Apple, Nvidia and SPY would be allocating product engineering in rough proportion to where its volume sits. It is doing the opposite. The financials book is a rounding error and it is where the build is going.

What the build buys is not fee income. It is the characterisation. On August 28 the Ninth Circuit held that the substance of Kalshi's sports event contracts is sports gambling regardless of what the exchange calls them, splitting with the Third Circuit and pointing the question at the Supreme Court. The single most dangerous idea in that opinion, for Kalshi, is that a venue can be looked through — that what matters is what the customer is doing, not what the rulebook says. An exchange whose product list runs from the NFL to the US equity market is a harder thing to look through than one that mostly books football. That is the asset being accumulated here, and it does not show up in a volume report.

What we do not know, and it is the number that matters most

The launch materials did not state a maximum leverage or a funding interval. Those are the two specifications a retail trader needs before taking a position, and neither was published in anything we could read. Reports on the crypto perpetuals have described leverage reaching 50x or more; Polymarket's September expansion into commodity, stock and index perpetuals advertises up to 20x and is walled off from US traders on its non-US platform. We are not going to extrapolate from either to US500PERP. We do not know what it allows.

Better Markets has been making the retail objection since the first approval, and its sharpest version is procedural rather than moral: the group asked the CFTC for enhanced disclosures on the bitcoin perpetual and the agency imposed none. In July, Benjamin Schiffrin wrote that perpetuals are complex and risky, that Kalshi describes them as simple, and that this is a misrepresentation of what the product is. He drew the analogy to single-stock ETFs, approved four years ago on the theory that retail investors would understand a leveraged daily-reset product, which many did not.

The analogy is sound and incomplete. Single-stock ETFs lose money slowly, through decay nobody reads about. A leveraged perpetual on a large-cap index liquidates, automatically, at a price. If an American retail trader is going to be able to take 20x on the US equity market from a phone app that also lists ten-leg NFL parlays, the leverage cap and the funding schedule should be on the first screen, not absent from the launch coverage. Kalshi has not said. It should.

Editor's note: TrueEdge builds odds and pricing tools and earns affiliate commissions from licensed sportsbooks, which compete with the exchange discussed here. We have argued against criminalising federally licensed exchanges; that position cuts against our own book and we state it anyway. Readers should weigh both.