Kalshi, Polymarket trading volumes on some products raises questions amid massive growth

Buying and selling volumes for sure merchandise on prediction market platforms Kalshi and Polymarket are elevating questions from some business observers, who concern the numbers could also be inflated.

On Polymarket, observers have flagged a quirk on the corporate’s worldwide alternate, which isn’t overseen by U.S. regulators: Markets that characteristic a number of contracts will see better exercise on these with decrease odds of occurring versus these with increased possibilities. It is seen on markets associated to elections, sports activities and central financial institution selections. 

In the meantime, a person on X on Sept. 20 flagged an odd sample on Kalshi’s perpetual futures marketplace for the ether cryptocurrency. Trades of round $5,500 made up a big share of transactions on the contracts, and that 24-hour buying and selling quantity was abnormally excessive in comparison with precise resting liquidity. A CNBC evaluation discovered that on Sept. 20, practically half of the greenback quantity traded on Kalshi’s ether perpetuals got here from trades sized between $5,495 and $5,505.

Each developments create issues amongst some observers that the businesses are overseeing inflated volumes or, at worst, are experiencing wash buying and selling, by which merchants collude to purchase and promote an asset to create a false sense of financial exercise. 

Each Kalshi and Polymarket deny wash buying and selling happens on any of their merchandise. Additionally they deny that the respective patterns signify inorganic exercise.

A delegated contract market, the kind of alternate prediction markets are, “has an obligation to guard market integrity by monitoring market situations, value actions, and volumes in actual time for abnormalities,” stated Tamika Bent, a companion at Okay&L Gates. “You’d count on DCMs to be surveilling uncommon quantity and searching into any indicators of market disruption.”

Polymarket is presently elevating at a valuation north of $20 billion within the personal market after the launch of its U.S. alternate in Might, whereas Kalshi is reportedly in talks to lift funds that will worth the corporate at $40 billion following its perpetual futures product debut in June. Each have used surging buying and selling volumes as a metric to underscore the exchanges’ rising recognition, serving to justify these valuations.

However as the businesses reportedly discover strikes to the general public markets as quickly as subsequent 12 months, the accuracy of those quantity figures is within the highlight.

“To the extent {that a} materials share of reported perpetual quantity is manufactured… headline quantity and its trajectory could overstate the underlying buying and selling demand on which such a valuation would relaxation,” Andre Guettler, a professor of finance at Ulm College in Germany, wrote in a working paper relating to the patterns on Kalshi’s perpetual futures’ quantity. “This distinction issues most for retail buyers, who’re the pure patrons of a prediction-market alternate at a public itemizing.”

Polymarket’s head of income and analytics Kyle Gesuelli informed CNBC that the recognition of its low-odds contracts is not from wash buying and selling or inorganic exercise. Fairly that is pushed by extremely lively merchants, known as “sharps,” discovering mispricing in varied contracts, he stated. 

“It is truly wholesome for markets as a result of it brings pricing imbalances again into steadiness,” Gesuelli stated.

Kalshi denied final week that it has any wash buying and selling on the platform, stating that it tracked a whole lot of customers concerned within the trades flagged initially on social media. Nevertheless, specialists CNBC spoke to stated that the ratio between day by day volumes and precise sitting liquidity on the contracts is worrying and represents an inefficient market construction that creates inorganic exercise.

Jack Such, a spokesperson for Kalshi, stated the corporate has “zero issues” about that ratio.

The Wall Road Journal reported the Commodity Futures Buying and selling Fee is analyzing the trades on Kalshi’s ether perpetual future contract. CNBC couldn’t independently confirm the report. A spokesperson for the CFTC stated that the company does not verify or deny issues associated to investigations. 

“We’ve a zero tolerance coverage on the subject of any type of manipulative buying and selling, together with wash buying and selling, insider buying and selling, or fraud in our markets,” CFTC Chairman Michael Selig stated in an look on CNBC’s “Squawk on the Road” final Wednesday. “When you’ve new kinds of markets evolving, you are going to see fraud with that.”

Low odds draw recognition

Barron’s reported in April that exercise on contracts associated to who will win the presidential election in 2028 on Polymarket’s worldwide alternate noticed uncommon exercise on low odds markets. 

A contract that requested if JD Vance would be the Republican presidential nominee in 2028 had much less quantity than one for Elon Musk, regardless of Musk not being eligible for the presidency. Comparable unusual quantity patterns had been discovered on markets associated to potential nominees for the Democrats within the 2028 contest. 

That is not the identical on its rival Kalshi’s markets, the place low-odds candidates for the presidency in 2028 have much less quantity than candidates with increased odds. Moreover, a CNBC evaluation of trades all through September decided the sample wasn’t detectable on 2028 presidential nominee-related contracts on Polymarket’s U.S. alternate, which is regulated by the CFTC. 

Uncommon exercise additionally occurred on Polymarket worldwide’s sports-related contracts. For the 2026 FIFA World Cup, victor Spain had $152 million traded on contracts associated to its odds to win the soccer event. Spain’s whole was lower than that of the $158 million traded on Egypt’s odds, which by no means crossed 0.5%, and it was barely smaller than Morocco’s, which by no means had a better than 2% likelihood of successful. 

Maybe most hanging is a contract that asks who would be the subsequent Prime Minister of Ethiopia. Prime Minister Abiy Ahmed, who gained that election and has 98% odds on the contract, has about $170,000 traded on his possibilities. In the meantime, Gedion Timothewos, whose likelihood has remained beneath 3% for months, has virtually $56 million traded on his odds. The contract remains to be lively, even because the election handed in June.

“These are ridiculous lengthy photographs,” stated Joe Saluzzi, head of fairness market construction analysis at Themis Buying and selling. “It appears like somebody’s making an attempt to place some very, very low threat quantity up there… Why would anyone be buying and selling that?”

A CNBC evaluation reveals quantity for the Ethiopian election jumped over 6.7 instances from June 21, when reviews confirmed Ahmed gained the election, to Sept. 25, in line with knowledge pulled from Dune Analytics. The best reported day by day quantity for the market was on July 30, recording over $15.3 million, over a month after reviews famous who gained. A Polymarket spokesperson informed CNBC that the contract will resolve when the federal government elected this summer time is formally sworn in. That’s slated for Oct. 5. 

Gesuelli stated that the low odds contract exercise is extra widespread on the corporate’s worldwide alternate as a result of it has a better variety of sharps, who typically are utilizing sophisticated software program and algorithms for his or her buying and selling exercise to make income off of small mispricings. The U.S. alternate is extra dominated by informal retail merchants, he stated. 

Worries about wash buying and selling on Polymarket aren’t new. A examine first launched in November 2025 by researchers at Columbia College discovered that buying and selling patterns it decided had been indicative of wash buying and selling accounted for 60% of Polymarket worldwide’s weekly quantity in December 2024, although it declined to twenty% in October 2025.

Lead writer Allen Sirolly stated the measure fell to a negligible quantity by April 2026. A Polymarket spokesperson stated expanded surveillance and the introduction of charges to the alternate have weakened possibilities for market manipulation. However Sirolly stated the lingering recognition of low-odds contracts is regarding. 

Many prediction market observers have chalked up the unusual discrepancies on Polymarket’s worldwide alternate to the hints it has given prior to now to conducting a cryptocurrency token “airdrop.”

Jay Maliava, co-founder and CEO at prediction market buying and selling terminal Kairos, defined that token airdrops are a typical manner for cryptocurrency-based firms to reward earlier customers of a platform that assist it scale and turn out to be related. Polymarket’s worldwide platform operates on the polygon blockchain. 

However who receives these rewards, in the event that they even occur, is not clear. Maliava stated it may vary, however platforms could evaluate customers’ open curiosity or particular person volumes to find out eligibility.

Polymarket declined to touch upon airdrop hypothesis. 

Kalshi’s ‘perps’ begin debate

Benoît Dubosson first flagged uncommon buying and selling conduct on Kalshi’s ether contract on Sept. 20. In a sequence of posts on X, he theorized the trades amounted to scrub buying and selling. 

Others raised questions over the authenticity of Kalshi’s buying and selling volumes. Critics claimed that incentives for market makers to supply resting liquidity, typical for a monetary alternate, and Kalshi’s waiver of buying and selling charges via the tip of 2026 in a bid to draw merchants to the corporate’s new futures product inspired this conduct.

Kalshi fired again on these claims in a weblog publish final Tuesday. It stated that a whole lot of customers had been concerned in these trades and stated it has mechanics in place to observe self-trades or collusion. The corporate as an alternative defined this was seemingly speculators conducting trades off of arbitrage, the place the spot value of a cryptocurrency is shifting on a unique alternate and is off barely from the place a market maker’s authentic order was. A dealer can then scoop up that barely outdated quote and acquire a fast revenue. 

Specialists that CNBC spoke with broadly agreed that the trades seemingly did not quantity to scrub buying and selling. However for Rajiv Sethi, an economics professor at Barnard Faculty, an issue nonetheless stays.

He stated Kalshi’s charge construction is permitting merchants to recreation the perpetual alternate and make these income constantly off of arbitrage. These income are solely doable, he stated, due to Kalshi’s buying and selling charge rebates it has carried out to draw early speculators to perpetual futures.

“What Kalshi is doing in a nutshell is that they’re funneling cash to aggressive liquidity takers via the market makers,” Sethi stated. 

Kalshi’s protection of those incentives — for each market makers and merchants taking the opposite aspect of those orders — is that they are important to supply early liquidity to a novel market. 

However how profitable these incentives are is undermined by the liquidity’s churn, specialists stated. Quantity on Kalshi’s bitcoin and ether perpetual futures is about 42 and 66 instances open curiosity on the platform as of Wednesday morning. That diverges considerably from different perpetual futures merchandise provided internationally. 

“It does not look very natural,” stated Guettler, the German finance professor, in an interview.

On Polymarket, 24-hour buying and selling quantity traded is about three-quarters of open curiosity on its ether perpetual futures, and on business chief Hyperliquid, 24-hour buying and selling quantity is only one third of open curiosity as of Wednesday morning. Each perpetual futures exchanges will not be out there within the U.S. 

“It is type of creating the looks of liquidity, nevertheless it looks like a self-licking ice cream cone,” Craig Pirrong, finance professor on the College of Houston’s C.T. Bauer Faculty of Enterprise, stated about Kalshi. “It appears to be liquidity that is supplied to reap the incentives.”

Such, the Kalshi spokesperson, stated that the variations between the 24-hour buying and selling volumes partially comes from the truth that the corporate presents decrease leverage on its contracts in comparison with offshore exchanges. Hyperliquid presents as much as 25 instances leverage on its ether perpetual future, whereas Kalshi solely permits merchants as much as 4.9 instances leverage. 

He added infrastructure and U.S. regulatory necessities additionally contribute to the distinction. Such stated Kalshi does not enable market makers to requote their orders if costs change, and that U.S. regulation does not allow the corporate to incentivize customers to park capital on the platform. 

Such additionally stated it isn’t truthful to match a CFTC-regulated alternate to ones working offshore. “That’s an apples and oranges comparability: they’re utilizing a unique system and enjoying by totally different guidelines.” Nevertheless, conventional bitcoin futures contracts on CME — a regulated U.S. alternate — additionally usually see quantity that’s lower than that of open curiosity. 

Nonetheless, Sethi believes that the discrepancy between quantity and open curiosity ought to trigger Kalshi to rethink among the incentives for its perpetuals alternate.

“I am not attributing it to scrub buying and selling,” Sethi stated. “However I disagree… that that is completely fantastic.”

Disclosure: CNBC and Kalshi have a industrial relationship that features buyer acquisition and a minority funding.