Stop Predatory Gambling has called on the United States Tennis Association to end its Kalshi partnership, arguing that prediction-market advertising and betting prompts at the US Open exposed the sport’s young audience to high-risk gambling.
The group’s letter to USTA chief executive Craig Tiley is dated Sept. 10, while separate coverage said it was sent Sept. 11. It asked the association to immediately stop promoting Kalshi during the tournament, saying the USTA’s duty to more than 100,000 junior players nationwide should take precedence over commercial considerations.
As we reported in August, the USTA put the exclusive Kalshi deal in place at the last minute for this year’s US Open. The agreement took effect immediately after qualifying, although its terms and parameters were not publicly clear. It also prevented other prediction-market platforms from advertising inside the venue and across television coverage, including ESPN.
Kalshi received courtside branding and sponsored prediction content distributed through the tournament’s official app. The Guardian and The Athletic both reported that the app sent Kalshi-labelled alerts or notifications featuring match predictions shortly after the partnership was announced.
Stop Predatory Gambling, which said it represented more than 6,000 members, described that integration as normalising “extreme forms of gambling” among the same youth demographic the USTA says it protects. Its letter also cited Wall Street Journal reporting on prediction-market marketing aimed at young adults and younger audiences. Daily Citizen reported that the letter noted some USTA junior players are old enough to trade on Kalshi, whose participation threshold is 18.
The group’s national director, Les Bernal, called the arrangement a “double fault of hypocrisy” and accused USTA executives of disregarding the risks. The USTA did not end the partnership before the US Open concluded.
Trading interest in tennis surged during the event. Kalshi users placed an average of $192 million a day on tennis during the Open, and tennis exceeded every other sport in betting volume on all but four tournament days. Tennis trading also substantially outpaced other sports during the first week.
The USTA said Kalshi’s presence at the tournament was limited. Tiley said the partnership was intended to advance fan engagement while safeguarding tennis integrity. Kalshi declined to comment.
The criticism arrived amid wider concern over gambling’s effect on tennis. A WTA and World Tennis review of the 2025 season found gamblers accounted for 42% of verified abuse, up two percentage points from 2024, and 59% of serious abuse. The Guardian also reported growing instances of spectators heckling or attempting to influence matches, with Lorenzo Musetti saying some bettors “disturb the game.”
The USTA had discussed match-integrity issues with multiple prediction-market platforms before finalising its Kalshi agreement, Front Office Sports reported. The ATP Tour, which does not operate the US Open, has separately urged the Commodity Futures Trading Commission to bar event contracts based on player injuries and officiating decisions.
