Compass Investments

Last month, the total trading volume on Kalshi and Polymarket declinedmarking the first month-over-month drop of the year following a surge in activity driven by the FIFA World Cup.

According to The Blocks analytics dashboard, the total monthly trading volume on Kalshi, Polymarket, and Polymarket US fell by 14.5% to $45.33 billion in August, marking the first decline since August 2025.

Specifically, trading volume on Kalshi in August reached $37.17 billion, which is 7.3% less than in July ($40.1 billion), while the combined volume on Polymarket and its U.S. platform totaled $8.16 billion, down 36.7% from Julys figure ($12.89 billion).

The August decline was a result of the summer surge in activity on prediction markets triggered by the FIFA World Cup, which ran from June 11 to July 19. Nevertheless, Augusts volume still significantly exceeds Mays level of $25.66 billion.

Meanwhile, both Kalshi and Polymarket are facing increased scrutiny from U.S. regulators, particularly regarding contracts related to sporting events. More than ten states have initiated enforcement actions or filed lawsuits against Kalshi and Polymarket.

Last week, the state of Connecticut filed a lawsuit against Kalshi, seeking to prohibit the platform from offering sports betting contracts, which has intensified the legal battle between the state and the platform that has been ongoing for several months.

Despite intensifying legal disputes with state authorities, Kalshi continues to expand its presence in the sports sector.

The company recently signed an agreement with the United States Tennis Association, becoming the exclusive prediction market partner for the U.S. Open, whose main draw began on August 30.

Meanwhile, earlier this week, Kalshi permanently banned former U.S. Representative George Santos from trading on the platformthe first permanent ban in the companys history. Santos violated the platforms rules by placing a bet on whether he would appear before Congress alongside the president and was required to pay a fine of more than $71,000.”,”detected_source_language”:”RU