Kalshi and Polymarket Volume Surge Draws Scrutiny as Odd Trading Patterns Emerge

Kalshi and Polymarket have become the loudest names in prediction markets, posting eye-catching growth in trading volume. Now a closer look at how that activity is distributed is raising an uncomfortable question: how much of it is genuine?

Analysts and market structure experts say certain contracts show patterns that do not look like ordinary retail speculation. Volume can spike in narrow products without a matching rise in the number of distinct traders, and some markets show heavy turnover with little change in price. Those are the kinds of signatures that can point to a small group of participants trading repeatedly among themselves, or to activity designed to inflate the numbers.

The concern matters because volume is the headline metric these platforms use to show momentum. It feeds into fundraising, partnerships, media coverage and the pitch to regulators and institutional users. If the figures overstate real interest, the picture of a fast maturing industry becomes harder to trust.

There are plenty of innocent explanations. Market makers, who post buy and sell orders to keep contracts liquid, can generate a lot of volume without taking a directional view. Incentive programs that reward liquidity provision can encourage frequent trading. And a newly launched product naturally behaves oddly while it finds its audience.

Wash trading, where the same party sits on both sides of a trade to fake activity, is the more serious worry. It is illegal in regulated futures markets, and Kalshi operates as a federally regulated exchange, which gives it formal obligations around surveillance and market integrity. Polymarket, which has built its reputation on crypto rails, has historically faced different oversight, though its push into the U.S. market is bringing it closer to the same expectations.

Experts say the answer is more transparency rather than less. Publishing counts of unique traders, separating market maker flow from customer flow, and giving independent researchers cleaner data would let outsiders judge which products have real depth. Without that, comparisons between the two platforms, and between prediction markets and traditional venues, rest on numbers that are hard to verify.

For investors weighing the sector, the takeaway is to look beyond the top-line figure. Open interest, the number of active accounts, and how tightly prices track real-world outcomes are better tests of whether these markets are working. The growth is real in many places. How much of it is organic is the part still being debated.