The prediction market sector sustained its upward trajectory through July, setting consecutive monthly records for both trading volume and overall activity. According to Artemis data, total volume across the sector reached $55.5 billion, up from $52.8 billion in June. Trade counts climbed to 383.9 million, compared with 332.2 million the previous month — marking back-to-back all-time highs during the same period that the World Cup knockout stages and final took place.

The tournament's knockout format aligned almost perfectly with the prediction market product. Each knockout fixture functioned as a short-dated binary event that settled within hours of the final whistle. Unlike open-ended questions about interest rate decisions or election outcomes months away, a team either advances or it does not — a short, binary, fast-settling structure that attracted millions of traders.

Kalshi Commands Roughly 70% Market Share During Record Month

While the entire sector expanded over the past two months, July stood out as a record specifically for Kalshi. The CFTC-regulated platform accounted for $38.6 billion of the $55.5 billion total volume and recorded 272.3 million of the 383.9 million trades. That translates to approximately 70% market share on both measures. Kalshi's designation as a designated contract market under CFTC oversight has allowed it to offer event-based contracts to US retail customers — a segment that crypto-native platforms operating offshore have limited ability to serve directly.

Kalshi's monthly trading volume has been in an uptrend since the start of the year, growing faster than any competing platform. July extended that lead further. Polymarket's absolute volumes have also grown over the past two months, but its share of the total market has continued to compress as the leader scales.

Five Platforms Beyond the Top Two Clear Nine Figures

Smaller venues beneath the top two are no longer negligible. Rothera cleared $1.7 billion in volume, and Nadex processed $1.1 billion, bringing two additional platforms into billion-dollar territory. Nadex, like Kalshi, operates as a CFTC-regulated exchange, meaning three of the top four platforms by volume now fall under US derivatives oversight. Opinion recorded $826.7 million, Predictdotfun $718.2 million, and Limitless $236.4 million. HIP-4 posted $123.8 million, while ForecastEx reported $28 million.

Taken together, these figures describe a market undergoing two simultaneous shifts: consolidation at the top, where Kalshi continues to capture share, and broadening at the bottom, where five or six venues now clear nine figures monthly. Both trends can coexist while the overall market expands this rapidly. The real test emerges when that growth plateaus.

Trade counts reveal distinct user profiles across platforms. Predictdotfun logged 15.6 million trades on $718.2 million in volume, indicating very small average ticket sizes. Kalshi and Polymarket dominate on both volume and trade counts, but the varying ratio between dollars and trades across the tail platforms suggests genuinely different customer bases rather than identical audiences competing for the same traders.

Weekly Volume Cools — A More Revealing Metric Than July's Total

Trading volumes have declined since the World Cup final, an expected outcome given that a tournament producing resolvable events every few days represents a temporary supply of trading opportunities. When the tournament concluded, that supply ended with it.

The more informative detail is where the decline stabilizes. Weekly figures have so far remained above the pre-June baseline, suggesting that a portion of the World Cup trading cohort continues to engage with other markets. If that pattern holds through August, the sector will have acquired durable users during the tournament rather than temporary participants. Conversely, if weekly volume continues sliding back toward May levels, July's figures will likely represent an event-driven spike rather than a sign of sustained sector growth. The coming months also bring event categories that prediction markets have historically tracked closely — including US political races and macroeconomic policy decisions — which could provide a fresh supply of resolvable events independent of the sports calendar.