Kalshi and Donald Trump Jr. have ended his strategic advisory role after 1789 Capital, the venture-capital firm where he is a partner, made a significant investment in rival prediction-market operator Polymarket. A Kalshi spokesperson said the company and Trump Jr. mutually agreed to end the role after the investment.
Trump Jr. had advised Kalshi since January 2025 and had also held a seat on Polymarket’s advisory board. Kalshi began ending the relationship during the summer, Sports Betting Dime reported. A company spokesperson said it was grateful for his work helping market Kalshi to more customers.
The arrangement had left Trump Jr. holding advisory positions at two companies the report described as the world’s largest prediction-market businesses. He received roughly $300,000 in Kalshi equity when he joined, according to the Financial Times report cited by Sports Betting Dime.
Polymarket had announced on Aug. 26, 2025, that 1789 Capital had made a strategic investment and that Trump Jr. was joining its advisory board. The companies did not disclose the investment’s terms. Trump Jr. was already a partner at 1789 Capital, which was founded in 2022 by Omeed Malik and Chris Buskirk and is based in Palm Beach, Florida.
In announcing the deal, Polymarket said the partnership would help it expand as a source of real-time information on public sentiment. The company described itself as the world’s largest prediction market and said users made about $6 billion in predictions during the first half of 2025.
Polymarket had completed its $112 million acquisition of QCEX, a CFTC-licensed exchange and clearinghouse, before announcing plans to re-enter the U.S. market. It had also named X as its official prediction-market partner.
