Polymarket's trading volume declined significantly in August as the prediction market industry cooled following the World Cup-driven surge that peaked earlier in the summer. Monthly volume dropped to $8.41 billion in August from $12.89 billion in July, representing a 35% decline, according to data compiled by The Block.
The core Polymarket platform absorbed the largest hit, with volume sliding from $7.89 billion in July to $4.59 billion in August. Polymarket US, the platform's separate product, fell more modestly from $5 billion to $3.82 billion.
Competitor Kalshi weathered the slowdown more effectively. Its volume eased from $40.1 billion in July to $38.67 billion in August, a decline of roughly 4%. The gap between the two platforms has widened considerably, with Kalshi now processing close to five times Polymarket's monthly volume.
The prediction market industry's volume spike earlier in the summer was driven by World Cup betting activity. Industry volume climbed from approximately $65 million at the beginning of July to a peak of $5.6 billion by the 22nd, driven by football-related markets that attracted first-time users. Data from DeFiLlama shows the pullback has continued into September, with weekly industry volume running around $4 billion.
Despite the trading slowdown, investor interest in the sector remains intact. Donald Trump Jr.'s venture capital firm, 1789 Capital, led a $1 billion funding round valuing Polymarket at $21 billion, a 40% increase from its approximately $15 billion valuation earlier in the year. Polymarket maintains more than 3 million users on its platform.
Both Polymarket and Kalshi continue to face legal challenges. Baltimore filed suit against both platforms last month, arguing they operate unlicensed sports betting operations. Kalshi is also defending against a lawsuit from New York Attorney General Letitia James, prompting the CFTC to invoke emergency powers to keep the platform operating in the state.
