Kalshi has become the exclusive prediction market partner of the US Open, Front Office Sports reported Sunday, citing two sources familiar with the agreement.
The deal reportedly took effect immediately, though it was not formally finalized until after last week’s qualifying rounds and before the main draw opened Sunday in Flushing Meadows. Financial terms were not disclosed.
USTA reportedly blocks rival prediction market ads
According to the report, the United States Tennis Association (USTA), which owns and operates the tournament, is barring rival prediction market platforms from advertising inside the venue and on television, including across ESPN’s broadcasts. One source described that term as “unusual.”
Front Office Sports said the USTA had planned to weigh prediction market partnerships for 2027 and beyond and, as of last week, had not formally approved the category at all.
The report also said Craig Tiley, who became USTA chief executive this year after more than a decade running Tennis Australia, pushed to get a deal done.
Even so, Kalshi still did not appear on the US Open’s official list of partners at the time of the report.
Kalshi led combined August volume
Kalshi, Polymarket, and Polymarket US have handled a combined $43.4 billion in volume so far in August, the report said. Of that total, Kalshi accounted for $35.55 billion.
Report follows fresh legal setback in the Ninth Circuit
The partnership report came two days after a legal setback for Kalshi. On Friday, the Ninth Circuit ruled that Kalshi had not shown that federal commodities law preempts Nevada’s gaming regulations for sports-event contracts.
That decision conflicts with an earlier Third Circuit ruling that blocked New Jersey from regulating the same products.
The split sharpens the dispute over whether the Commodity Futures Trading Commission, or CFTC, or state gaming regulators control the category. It also brings the issue closer to a Supreme Court fight.
New York, Washington, and Michigan remain pressure points
Kalshi is still facing other legal and regulatory pressure. New York is seeking at least $36 billion over alleged unlicensed gambling, and courts in Washington and Michigan have restricted its sports contracts.
Even with that uncertainty, prediction market companies have kept collecting sports-property partnerships.
- Kalshi and Polymarket are both official NHL partners.
- Polymarket has the league-level deal with MLB and an agreement with the Yankees.
- Kalshi has team-level deals with the Blackhawks and MLB’s Giants, Braves, Padres, Red Sox, and Dodgers.
The NFL and NBA remain outside the group.
Nevada judge and ATP have also weighed in
In April, a Nevada judge extended a ban on Kalshi’s sports contracts, calling them indistinguishable from gambling.
The ATP, in an April comment letter to the CFTC, said it supports rules for sports-event contracts, including a prohibition on contracts tied to player injuries and officiating decisions.