Donald Trump Jr. exits Kalshi advisory role after firm invests in Polymarket

Advisory role ends after rival investment

Kalshi and Donald Trump Jr. have agreed to end his advisory role with the prediction market platform, according to Ars Technica. The decision came shortly after news that Trump Jr.'s venture capital firm, 1789 Capital, made a large investment in Kalshi's main competitor, Polymarket.

Kalshi said in a statement that the two sides mutually agreed to part ways after the firm's significant investment in a competitor in the summer, and thanked Trump Jr. for helping market the platform to more customers. A Kalshi spokesperson told Ars Technica that internal discussions began in August, when the Polymarket investment became public, and that both parties understood advising two competitors in a growing sector was becoming complicated.

Equity stakes in both platforms

Trump Jr. joined Kalshi as a strategic adviser in January 2025, receiving equity then worth about $300,000, according to the Financial Times. Kalshi was valued at under $2 billion at that point. Its valuation has since risen sharply, reaching $22 billion in a recent funding round, with reports of talks for a new round at $65 billion. The Financial Times reporting suggests Trump Jr. may still hold a financial interest in the company.

He also has ties to Polymarket through his role as a partner at 1789 Capital and as an adviser to that platform. The venture firm invested $300 million in Polymarket in August 2026, building on a smaller investment a year earlier. Kalshi's chief executive, Tarek Mansour, acknowledged in an interview with MS Now that the arrangement created what he described as an optics issue.

How the advisory role began

Mansour has claimed the appointment was not political and was made before the election. However, Kalshi announced Trump Jr.'s role on 13 January 2025, more than two months after the November 2024 presidential election and a week before Donald Trump's second inauguration.

In a post on X at the time, Trump Jr. said he decided to help Kalshi after his family used the platform to follow the election results on election night at Mar-a-Lago. Mansour told MS Now that Kalshi never had any policy or regulatory involvement from Trump Jr., and that the role was about marketing: explaining prediction markets to a broad audience. He noted Kalshi has advisers from both parties and that Trump Jr.'s large social media following made him a useful promoter.

Political scrutiny and legal context

The departure follows a 9 November letter from US Senators Elizabeth Warren and Jeff Merkley to White House Counsel Will Scharf raising concerns about Trump Jr.'s stakes in both Kalshi and Polymarket. They cited an insider trading case in which a Trump teleprompter aide won more than $100,000 betting on the president's prepared remarks using Kalshi's mention markets. The Commodity Futures Trading Commission, the federal agency that regulates these markets, ordered the aide, Gabriel Perez, to give up profits of $107,539.02 and pay a $65,000 penalty.

According to Ars Technica, the CFTC is reportedly close to bringing charges against Kalshi over alleged failures to notify the agency about dozens of new event contracts. At the same time, the agency has sided with prediction market operators against state regulators, suing 10 states before filing a case against Arkansas this week.

Why it matters

Prediction markets let people bet real money on the outcomes of real-world events, from elections to sports. The sector has grown quickly and now sits at the intersection of finance, gambling and politics.

The episode highlights close ties between the Trump family and an industry that has benefited from the administration's legal and regulatory support. Warren and Merkley argue the president's family stands to profit personally from the industry's success while the White House has not strengthened ethics rules. Kalshi has also paid former Senator Blanche Lincoln as a lobbyist since 2024, despite her earlier statements against using event contracts for sports betting. Trump Media and Technology Group announced plans last year for a Truth Predict market on Truth Social with Crypto.com, but those plans appear to have been scaled back.