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

Kalshi and Polymarket.Gabby Jones | Bloomberg | Martin Lelievre | Getty ImagesTrading volumes for certain products on prediction market platforms Kalshi and Polymarket are raising questions from some industry observers, who fear the numbers may be inflated. On Polymarket, observers have flagged a quirk on the company's international exchange, which is not overseen by U.S. regulators: Markets that feature multiple contracts will see greater activity on those with lower odds of occurring versus those with higher probabilities. It's seen on markets related to elections, sports and central bank decisions. Meanwhile, a user on X on Sept. 20 flagged a strange pattern on Kalshi's perpetual futures market for the ether cryptocurrency. Trades of around $5,500 made up a large share of transactions on the contracts, and that 24-hour trading volume was abnormally high compared to actual resting liquidity. A CNBC analysis found that on Sept. 20, nearly half of the dollar volume traded on Kalshi's ether perpetuals came from trades sized between $5,495 and $5,505. Both developments create concerns among some observers that the companies are overseeing inflated volumes or, at worst, are experienci...