Kalshi reported robust trading last week, with sports markets accounting for nearly 75% of trading volume. The leader was the British Open, and it accounted for more than 15% of all trading volume, followed by the MLB, UFC, and other sports markets, including tennis, WNBA, and MLS.

Prediction market platform Kalshi saw a major surge in sports-related trading activity last week, with nearly three-quarters of all trading volume driven by athletic events. Leading the pack was the British Open, which emerged as the single most active market during the week of July 14 to July 20 - thanks in part to Scottie Scheffler’s commanding performance on the final day of the tournament.

The latest volume report from Kalshi highlights growing interest in sports markets, while also revealing a sharp concentration of user engagement around a small number of topics. According to the report, the platform's top 20 markets accounted for more than 90% of all trades during the week.

Golf dominates with British Open bets

The British Open was responsible for more than a quarter of all trading on Kalshi last week, securing its place as the top-performing market by volume. Although Scheffler's eventual victory seemed inevitable as he pulled ahead on Sunday, traders remained active in side markets - particularly on predictions involving top 10 finishes for various players.

This surge in golf-related trading demonstrates Kalshi's growing appeal to sports bettors looking to test their predictions in real time using the regulated prediction market format. The tournament's visibility and high-stakes drama translated directly into increased trader participation.

Baseball and UFC fuel additional growth

Following closely behind golf were a number of baseball-related markets, including single-game Major League Baseball wagers, the MLB Home Run Derby, and the All-Star Game. Combined, these markets accounted for more than 20% of the week's total trading volume.

Mixed martial arts also made a significant showing, with betting on UFC 318 accounting for over 13% of all activity. The popularity of combat sports on Kalshi reflects a wider trend of fan engagement with fast-moving, outcome-driven events that are ideal for prediction market trading.

Other notable sports markets in the top 20 included individual tennis matches, WNBA games, and Major League Soccer matches. In total, 8 of the top 10 markets - and 11 of the top 20 - were tied to sports events.

Crypto and pop culture round out the top 20

While sports ruled the trading landscape, several non-sports markets still managed to make the top 20 list. Cryptocurrency markets had a strong presence, with Bitcoin and Ethereum price predictions (both absolute and range-based) appearing multiple times on the leaderboard.

In a more unusual twist, one of the week's top-performing markets stemmed from a viral news story. A market on whether Andy Byron, the CEO of Astronomer, would step down after being caught in a public scandal at a Coldplay concert quickly attracted attention and earned a spot in the top 20.

Economic and political questions maintain a foothold

Despite the overwhelming dominance of sports, traditional political and economic markets still held some ground. Traders remained active in forecasting Federal Reserve decisions on interest rates, the outcome of the New York City mayoral race, and whether Jerome Powell would remain as Fed Chair through the end of the year.

Markets predicting inflation rates, S&P 500 closing prices, and the identity of the 2028 Democratic presidential nominee also made the cut, showing that Kalshi users are still keen to engage with macroeconomic and political developments.

Although Kalshi offers over a thousand active markets at any given time, the latest report makes clear that user attention remains heavily focused on a select few. The top 20 markets captured more than 90% of all trading activity, leaving minimal volume spread across the rest of the platform.