First monthly decline: Combined trading volume on Kalshi and Polymarket fell to $45.33 billion in August

Odaily News: The combined monthly trading volume of Kalshi and Polymarket dropped to $45.33 billion in August, down 14.5% month-over-month, marking the first monthly decline since August 2025. Trading volume on prediction markets rose during the World Cup period from June 11 to July 19, but fell back in August after the event concluded. Kalshi's August trading volume was $37.17 billion, down 7.3% month-over-month; the combined trading volume of Polymarket and its U.S. platform was $8.16 billion, down 36.7% month-over-month. August's trading volume was higher than May's $25.66 billion.