Roughly 70% of all closed markets on Polymarket recorded under $10,000 in reported trading volume between 2021 and the end of May 2026, a CNBC analysis found.

The findings land as prediction markets post surging volume, driven by the 2026 FIFA World Cup. That gap shows how a small group of marquee contracts, rather than the broader platform, captures most of the money.

Most Polymarket Closed Markets Traded Under $10,000

CNBC pulled closed-market data from Polymarket’s Gamma API, which counts notional volume on both sides of each trade. The distribution came out heavily skewed.

Fewer than 10% of closed markets drew between $100,000 and $1 million in reported volume. More than 45,000 markets, close to 5% of the total, showed no reported volume at all.

Bots dominate the thin end. Joshua Della Vedova, a business professor at the University of San Diego, found that more than 80% of the volume in sub-$10,000 markets came from bots.

He defined bots as wallets that make more than 50 trades a day or more than 1,000 in total. By his estimate, they earned roughly $1.2 million in markets under $10,000, but about $50.5 million in the $1 million to $10 million range. 

That tier made up 38% of total bot profit. Markets above $10 million added a further $35.1 million.

“They are making money across all markets,” Della Vedova said. “(Bots) make money per transaction, and therefore they prefer to trade in these larger markets, but they will trade across the whole spectrum.”

The report added that Kalshi also recorded a significant number of shallow markets, based on an analysis of the on-chain data from Dune. However, unlike Polymarket’s Gamma API, Kalshi’s notional volume figures on Dune account for only one side of each trade.

World Cup Bets Fuel Prediction Market Growth

The thin-market picture contrasts with headline growth. Weekly World Cup volume across major venues climbed from $65 million in the week of June 1 to $5.4 billion by June 29, according to CryptoRank data.

Volume peaked at $5.6 billion in the week of June 22. Kalshi led the climb, showing how major sports events can quickly drive demand for prediction trading.

That growth sits alongside the thin tail. The money concentrates in a small set of high-profile contracts, while tens of thousands of markets see almost no activity.

BeInCrypto has reached out to both Polymarket and Kalshi for comment.

Source: BeInCrypto