Polymarket's trading volume in August declined to $8.41B from $12.89B in July — a 35% drop driven by a slowdown in prediction market activity following the end of the World Cup. As CryptoPotato reports, this deceleration contrasts with the surge seen in July, when the FIFA World Cup drew a wave of new users to prediction platforms. At peak activity in mid-July, industry-wide trading volume reached $5.6B, though it stood at just $65M at the start of the month. Polymarket's core platform fell even harder: its volume shrank from $7.89B in July to $4.59B in August, while Polymarket US declined from $5B to $3.82B. In September, the sector continued to cool — weekly trading volume came in at around $4B, well below the figures recorded during the tournament.
Polymarket's rival Kalshi weathered the slowdown far more comfortably: its August trading volume came in at $38.67B versus $40.1B in July, a decline of just 4%. Over the half-year period, Kalshi climbed from $33B in June to $40.1B in July. The gap between the platforms has widened considerably: Kalshi now processes roughly five times the monthly volume of Polymarket. Meanwhile, according to Predictefy, the most recent divergence figure differs: Polymarket's 30-day volume stands at $3.8B compared to $11.28B for Kalshi. Different sources report different monthly trading volume figures, pointing to discrepancies in methodology or data coverage. Despite the volatility, Polymarket continues to attract more than 3 million users, underscoring the platform's broad reach among prediction traders.
The pullback in trading activity has not dampened investor interest in the sector. Venture firm 1789 Capital, backed by Donald Trump Jr., led a $1B funding round that pushed Polymarket's valuation to $21B — a 40% increase from its previous valuation of $15B. That said, both platforms continue to face legal challenges. Baltimore has filed a lawsuit against Kalshi and Polymarket, alleging the companies operate as unlicensed bookmaking operations. Kalshi is also in litigation with New York Attorney General Letitia James; the Commodity Futures Trading Commission (CFTC) recently invoked emergency powers to allow Kalshi to continue operating in the state.