Kalshi Signs Exclusive U.S. Open Prediction Market Deal With USTA

Prediction market platform Kalshi has signed an exclusive agreement with the United States Tennis Association to become the U.S. Open's sole prediction market platform partner. The deal took effect immediately and was finalized after last week's qualifying rounds, with no financial terms disclosed. According to ChainCatcher, the agreement also bars other prediction market platforms from advertising at U.S. Open venues and on television broadcasts, including ESPN coverage of the tournament. Kalshi is not yet listed among the U.S. Open's official partners, and a prior blog post analyzing the women's singles event said the company had no affiliation with the U.S. Open or the WTA. Sources said USTA CEO Craig Tiley, who took office on July 20, played an important role in securing this year's tournament agreement. Kalshi and Polymarket are both official NHL partners, and Kalshi has also recently partnered with several MLB teams. Data from The Block shows that since August, combined trading volume across Kalshi, Polymarket, and Polymarket US has reached $41.2 billion, with Kalshi accounting for $33.7 billion.