Kalshi has ended its advisory contract with Donald Trump Jr. after his venture capital firm, 1789 Capital, increased its stake in rival prediction market Polymarket, Reuters reported Thursday.
“We have mutually agreed to end Don’s advisory role after his firm’s significant investment in a competitor this past summer. We are grateful for his contributions in helping us market Kalshi to more customers,” a Kalshi spokesperson said.
The spokesperson said talks to part ways began in August, after 1789 led Polymarket’s most recent funding round. That excuse does not entirely wash, though, as 1789 invested a reported $200 million into Polymarket last year while Trump Jr. was already an advisor for Kalshi.
His removal comes a little more than a week after Democrats won control of both the House and the Senate. Some have already started calling change, with Rep. Ro Khanna calling on Congress to ban sports predictions entirely.
Polymarket and Trump Jr. did not immediately respond to Reuters.
Trump Jr. advised both rivals since 2025
The split ends an unusual arrangement in which the president’s son held advisory roles at the two biggest U.S. prediction markets at the same time.
Kalshi named Trump Jr. a strategic advisor in January 2025, a week before his father took office for his second term. He received equity the worth $300,000 at the time. He then joined Polymarket’s advisory board in August 2025, when 1789 first invested.
Both companies’ valuations soared while Trump Jr. was part of each. Kalshi hit $40 billion in October, while Polymarket reached $21 billion in August.
Pressure mounting on Trump Jr.
Prediction markets expanded rapidly during President Trump’s second term. Days after he took office in January 2025, Kalshi self-certified sports event contracts for the Super Bowl.
Trump Jr.’s ties to the industry have drawn attention from both parties. Sen. John Curtis, a Utah Republican, asked the Senate Judiciary Committee in a Sept. 21 letter to investigate whether presidential family members have used their access for private financial gain. Curtis specifically cited Trump Jr.’s ventures in cryptocurrency, international real estate, defense contracting and prediction markets. He also urged the committee to subpoena Hunter Biden.
“This pattern extends to his significant financial and advisory ties to prediction-market platforms that depend on favorable federal regulatory decisions being considered by the Commodity Futures Trading Commission,” Curtis wrote.
Democrats have also stepped up scrutiny. Sens. Elizabeth Warren and Jeff Merkley wrote White House counsel Will Scharf on Monday asking what safeguards prevent staff from trading on confidential information. The letter, prompted by allegations that Trump’s teleprompter operator profited on Kalshi, also noted Trump Jr.’s ties to the industry.
Prediction markets are regulated federally by the CFTC and aren’t subject to the same responsible gambling requirements as state-regulated sportsbooks. State regulators and lawmakers in many states argue the contracts amount to sports betting and belong under state oversight, a fight that is now playing out in courts across the country.
