Kalshi Ends Donald Trump Jr.’s Advisory Contract Over Polymarket Conflict

Kalshi has ended Donald Trump Jr.'s advisory contract after his venture capital firm increased its investment in rival prediction-market operator Polymarket.

The company confirmed the departure Nov. 12, saying the decision was mutual and followed a significant investment by 1789 Capital, where the president's eldest son is a partner.

"We have mutually agreed to end Don's advisory role," Kalshi spokesperson Dani Lever told Reuters.

Kalshi said discussions began in August, when 1789 Capital led another funding round for Polymarket. The company denied that political considerations influenced the decision.

However, Reuters reported that some within Kalshi had raised concerns about possible congressional scrutiny of Trump Jr.'s involvement.

Trump Jr. joined both prediction-market companies

Kalshi appointed Trump Jr. as a strategic adviser in January 2025, shortly before his father's second presidential inauguration. At the time, co-founder and CEO Tarek Mansour said Trump Jr. would help the company expand its audience, develop partnerships, and bring prediction market apps into the mainstream.

Trump Jr. received an equity stake in Kalshi reportedly worth more than $300,000, according to The New York Times. Seven months later, Polymarket announced that he had joined its advisory board, alongside a strategic investment from 1789 Capital.

The Aug. 26 announcement did not disclose the investment's value.

Trump Jr. maintained relationships with both companies until Kalshi ended his advisory agreement this month. No corresponding departure from Polymarket has been announced.

Polymarket investment grows substantially

The financial relationship expanded in 2026. According to a September report from The New York Times, 1789 Capital was leading a planned $1 billion fundraising round for Polymarket at a $21 billion valuation.

The firm's spokesperson said it expected to contribute about $300 million, after previously investing about $200 million. Those are investments attributed to 1789 Capital, not personal contributions from Trump Jr.

Kalshi said the additional investment created a conflict with its own business interests, prompting discussions that eventually ended the advisory arrangement.

The split comes as prediction markets continue expanding their reach in sports, politics and other event-based contracts.

Both Kalshi and Polymarket have pursued growth in the United States while navigating ongoing disputes over federal regulation and state gambling laws.

Congressional scrutiny continues

The timing also coincides with increased attention from Washington.

In a Nov. 9 letter to White House Counsel David Warrington, Democratic Sens. Elizabeth Warren and Jeff Merkley questioned the administration's safeguards against prediction-market insider trading.

The inquiry followed allegations that a former White House aide used advance knowledge of presidential speeches to profit from event contracts. The senators also raised concerns about Trump family financial interests in prediction-market businesses and the potential for conflicts involving federal oversight.

They requested answers by Nov. 23.

Those concerns are separate from Kalshi's stated reason for ending Trump Jr.'s contract, and the letter does not establish wrongdoing by him. Trump Jr. has previously defended his private investments, telling The New York Times that he holds no policymaking position within the administration.

Kalshi's departure from the arrangement removes one of his direct advisory relationships in the industry, but his firm's financial backing of Polymarket remains central to the story.

With prediction markets expanding rapidly and lawmakers examining their oversight, the industry's political and financial relationships are likely to face continued attention.