Prediction platform Kalshi has reported one of its strongest performances in nearly a year. It has surpassed rival Polymarket in trading volume and claimed a majority share of the global market, according to The Block.
Key Takeaways
- Kalshi has captured 62.2% of global prediction market volume, rising from 3.1% one year ago.
- The platform has recorded $1.3 billion in September trading volume, ahead of Polymarket's $773 million.
- Analysts see prediction markets growing as crypto, AI, and news increasingly converge.
The company stated it now accounts for 62.2% of global prediction market activity, a sharp increase from just 3.1% a year ago. Despite being limited to U.S. consumers, Kalshi's monthly volume has already reached $1.3 billion in September, compared to Polymarket's $773 million.
The last time Kalshi crossed the $1-billion monthly mark was during the U.S. elections in November 2024. While the month has not ended, and Polymarket could potentially close the gap, recent data indicate Kalshi has been gaining steady momentum.
Although both platforms saw a slowdown following the 2024 election cycle, analysts suggest that growing interest in prediction markets and potential valuations could drive renewed growth.
Massachusetts lawsuit challenges Kalshi's operations
Despite its recent trading success, Kalshi is facing legal headwinds in Massachusetts as Attorney General Andrea Campbell recently filed a lawsuit in Suffolk County Superior Court, accusing the company of illegally operating as a sportsbook without a license.
Regulators argue that more than $1 billion in wagers were placed on sports events during the first half of 2025. Sports-related markets made up over 75% of Kalshi's overall activity.
The lawsuit claims Kalshi's platform functions in ways similar to online gambling sites, incorporating behavioral design methods drawn from casino-style mechanics. Regulators highlighted the introduction of a parlay product as evidence that Kalshi is crossing into sports betting territory.
Officials also pointed to the company's marketing, which they allege positions the platform directly alongside licensed operators such as DraftKings and FanDuel.
This lawsuit adds to growing scrutiny of fintech companies moving into sports event trading. Earlier this year, Massachusetts regulators reviewed Robinhood's contracts tied to sports outcomes, raising similar concerns about whether prediction platforms are operating outside legal sportsbook frameworks.
Polymarket re-enters U.S. market
While Kalshi confronts regulatory challenges, Polymarket is preparing for a regulated return to the U.S. after receiving a no-action letter from the Commodity Futures Trading Commission (CFTC). Despite losing its U.S. license in early 2022, the platform continued to function as an offshore crypto-based prediction market.
The company has completed a $112-million acquisition of derivatives exchange QCX and its affiliated clearinghouse QC Clearing, collectively known as QCEX. The move secures Polymarket access to a CFTC license, allowing it to legally offer event-based contracts in the U.S.
Polymarket, which has operated globally as a blockchain-based platform for political, cultural, and sports markets, saw significant activity during the 2024 presidential election. With the regulatory barrier now removed, the company is positioned to re-establish itself in the American market under federal oversight.
