Invest2 publishers3 min readPublished
Kalshi's ether perpetual turned over its open interest 174 times in a day
A former quant put $538.6m of 24-hour volume beside $3.1m of open interest on Kalshi's ether perpetual and called it proof of wash trading. Kalshi's crypto lead answered that the dollar sign means notional payout.
The Investor · Invest desk

What happened
- Beni, a former quant and co-founder of Stealth Neolab, posted screenshots showing about $538.6 million of 24-hour volume on Kalshi's ether perpetual against roughly $3.1 million of open interest.
- He tied the pattern to a CFTC filing under which eligible self-clearing members collect a 0.3-basis-point maker rebate while takers pay 0.3 basis points, netting to zero on some trades.
- So far the dispute sits at public screenshots and filings against Kalshi's explanation, with no regulator having announced an enforcement action tied to the ether-perp claims.
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Why it matters
- contradiction The notional-payout defence leaves the 174x reading intact: the convention inflates a dollar figure, but both $538.6m and $3.1m come from Kalshi's own screens, so dividing one by the other cancels it.
- constraint At 0.3 basis points, a $538.6m day of ether-perp turnover pays about $16,000 in taker fees, too little for volume growth on this book to carry a revenue case for the product.
- exposure Kalshi's CFTC registration is what put the fee schedule in a public filing, so the numbers a critic used against it came from the exchange's own paperwork.
- decision Anyone sizing prediction-market venues off displayed volume now has to quote open interest alongside it, and on the ether perpetual that figure is $3.1 million.
Kalshi's glossary defines volume as the number of contracts traded, and the interface prints that count with a dollar sign in front of it [8]. Spend $30,000 on 100,000 contracts priced at 30 cents and the screen reports $100,000 of volume [9], three times the cash [5]. IcoBeast.eth, Kalshi's crypto lead, says that is the notional-payout convention other prediction platforms use, each contract worth $1 at settlement, so the headline figure is a maximum payout, not money laid out [18]. The convention deflates a dollar figure by the average contract price. A ratio built from two Kalshi figures is untouched by it, because the same convention sits above and below the line. $538.6m over $3.1m is 173.7 [1], and scaling both by the same factor leaves it there. Which basis the open-interest number uses is unclear from the published account of the dispute.
The repeated lot is the harder number to explain. Beni says the same $5,500 size accounted for 48 to 58 percent of all ether-perp volume on four separate days [5]. Take the low end of that against a $538.6m day and you need roughly 47,000 identical prints in 24 hours, one every 1.84 seconds [3]. A uniform child-order size is also what an execution algorithm produces. A single market maker quoting both sides and flattening inventory intraday can generate very large turnover while leaving almost nothing on the book. Beni wrote: "Kalshi fakes their crypto volume and I can prove it" [16], and he called the repetition "undeniable proof" of manufactured activity, saying he had archived the data in case it later disappeared [6].
The fees are small in both directions. At 0.3 basis points a $538.6m day collects about $16,000 from takers [2]. That is the whole revenue line at that rate. The same 0.3 basis points paid back to the maker is what the incentive argument rests on, since a self-clearing member on both sides of its own trade nets to zero [7]. Beni took those numbers from a CFTC filing [7] and also cited a reported Jump Trading arrangement in which liquidity provision was linked to an equity stake [19]. IcoBeast said suspected wash trades and self-matching are excluded from rebates [13], and that the cited rebate program does not cover Kalshi's crypto event contracts [11]. Self-clearing membership, he said, is open to any firm meeting regulatory capital and operational tests, because CFTC rules require "fair access" [12]. Both men can be right if the filing covers a product other than the perpetual.
Beni's screenshot of the public leaderboard puts the largest ether-perp holding at $17,598 [4], which is 0.57 percent of the $3.1m of open interest [4]. Either the rest of the book is spread across hundreds of accounts in similar size, or the leaderboard shows part of it.
The $538.6m tells you how much turnover the venue can display; the $3.1m tells you how much capital is at risk in the contract. On what has been published, the ratio alone falls short of proving wash trading, and no regulator has announced an enforcement action tied to the claims [14]. Counterparty or self-match data on the $5,500 prints would settle it, as would open interest that climbs while volume holds. Incentive programs at a CFTC-regulated venue must be filed publicly, unlike the private deals common at offshore exchanges, according to IcoBeast [15].
What to watch
- Whether Kalshi publishes counterparty or self-match data on the repeated $5,500 ether-perp prints.
- Whether ether-perp open interest climbs from $3.1m while volume holds, or the ratio stays near 174x.
- Any CFTC action, or an amended Kalshi incentive filing covering perpetual maker rebates.