Kalshi becomes exclusive prediction market partner of US Open: report

Kalshi has signed an exclusive deal with the U.S. Tennis Association (USTA) to become the exclusive prediction market platform partner of the US Open tennis tournament, whose main draw began Sunday in Flushing Meadows, New York, according to a report from Front Office Sports (FOS).

Per the report, which cites two sources familiar with the deal, the agreement goes into effect immediately and was not formally finalized until after the tournament's qualifying rounds concluded last week. The report did not disclose the financial terms of the deal. 

The US Open, which is owned and operated by the USTA, was planning to consider prediction market partnerships for 2027 and beyond. However, USTA CEO Craig Tiley, who took office on July 20 of this year, played a major role in securing a deal for this year's tournament, according to FOS.

Per one of the sources, the USTA is reportedly preventing other prediction market platforms from advertising both at the US Open venue and on television, including across ESPN's broadcasts of the tournament, marking an unusual aspect of the deal. 

Kalshi was not listed among the US Open's official partners as of Sunday afternoon. A blog post published by Kalshi earlier in the day analyzing the women's singles tournament also contained a disclaimer stating that the company was "not affiliated with the U.S. Open or WTA," the FOS report noted. 

Kalshi declined to comment to FOS, while representatives for the USTA and ESPN did not immediately provide comment. Kalshi also did not immediately respond to a request for comment from The Block. 

Prediction markets push further into sports

Partnerships with major sports teams are becoming par for the course for prediction market platforms like Kalshi and Polymarket, and even newer entrants like Novig, which struck a deal with the New York Mets to become the first prediction market platform to partner with an individual Major League Baseball team. 

Kalshi and Polymarket are both official partners of the NHL, while Polymarket has deals with Major League Baseball and the New York Yankees. Kalshi recently announced partnerships with several MLB teams, including the Atlanta Braves, Boston Red Sox, Los Angeles Dodgers, San Diego Padres and San Francisco Giants. 

Sports have also become central to the platforms' businesses. Kalshi, Polymarket and Polymarket US generated a combined $41.2 billion in trading volume so far in August, according to The Block's data dashboard, with Kalshi accounting for $33.7 billion. 

Sports-related contracts continue to drive significant volume on Kalshi; a recent rise in The Block's "Other" category appears to be the result of combination or parlay-style "Exotics" markets gaining in popularity, though most of those markets are themselves sports-related. 

News of Kalshi's US Open deal comes as the platform continues legal battles with state regulators over whether its CFTC-regulated sports-event contracts are subject to state gambling laws.

On Friday, the Ninth Circuit Court of Appeals dealt Kalshi a setback in its dispute with Nevada by ruling that the company had not shown that federal commodities law preempts Nevada's gaming regulations with regard to sports-event contracts.

The decision conflicts with an earlier Third Circuit ruling that prevented New Jersey from regulating Kalshi's sports contracts, deepening a split over the respective authority of state gaming regulators and the Commodity Futures Trading Commission.