$50.6 billion. That's how much traders moved through prediction markets in July, smashing the previous record. The space is consolidating fast, with one platform controlling nearly three quarters of the action.
Kalshi alone captured $37.7 billion of that July volume, or about 74.5% of the entire market. The platform has become the heavyweight in what was once a scattered ecosystem of event-betting venues. Polymarket's US operation, meanwhile, posted a 54% jump to $5 billion for the month, showing that despite Kalshi's dominance, there's still meaningful competition fighting for share.
The settlement squeeze
Open interest in these markets actually contracted during the period. It fell to $1.2 billion after a major batch of World Cup contracts settled out, which is typical when a big event wraps and positions get cleared. Traders don't leave their money sitting idle between high-stakes events, so the drop reflects the natural rhythm of the market rather than any loss of confidence.
Regulatory headwinds mount
The explosive growth is now drawing heavyweight attention from regulators. New York filed suit against Kalshi in July, challenging whether the platform operated within state gambling and securities laws. A Minnesota judge also weighed in with restrictions that could ripple across the industry. These moves suggest that as prediction markets shift from fringe product to mainstream trading vehicle, the legal framework around them is still being written.
The concentration in Kalshi's hands raises a different question too. When one platform controls nearly 75% of volume, it means liquidity pools there and price discovery happens on one stage. That works until it doesn't, and any operational hiccup or regulatory blow could shake the entire ecosystem. For now though, traders keep showing up.
This material is for informational purposes only and does not constitute financial or investment advice.
