What We Know About Donald Trump Jr.'s Exit From Kalshi

Donald Trump Jr. has stepped down as a strategic adviser to the prediction-market platform after his venture capital firm poured money into a competing site, the company said this week, according to Ars Technica.

Why did Trump Jr. leave the advisory role?

"We have mutually agreed to end Don's advisory role after his firm's significant investment in a competitor this past summer," the firm said in a statement given to Ars Technica and other outlets. "We are grateful for his contributions in helping us market Kalshi to more customers."

A spokesperson added that talks about the move began in August, when word surfaced that Trump Jr.'s venture firm, 1789 Capital, had invested heavily in Polymarket. "Kalshi reached out to Don Jr. this fall to discuss his firm's increased investment in our top competitor and his role on its advisory board… both parties understood that advising two competitors in a growing sector was complicating things for both of us," the spokesperson said, per Ars Technica.

What was Trump Jr.'s financial stake?

Trump Jr. joined as a strategic adviser in early 2025 and received roughly $300,000 worth of equity at the time, the Financial Times reported in June, according to the Ars Technica account. That stake was granted when the company was valued at under $2 billion — far below the $22 billion valuation set in a funding round last spring. The firm is reportedly now in talks for a new round that would value it at $65 billion. It is not clear from available reporting whether Trump Jr. still holds that equity after ending his advisory work.

How is the Trump administration connected to the business?

The Commodity Futures Trading Commission has taken a permissive regulatory stance toward prediction markets under the current administration and has sued 11 states in an effort to block state-level restrictions on the industry, Ars Technica reported. The agency has also filed briefs backing the company in its own legal fights with individual states, where attorneys general have accused it of running an illegal gambling operation.

Co-founder and CEO Tarek Mansour addressed the overlap in an interview with MS Now last month.

"I get asked a lot about Don. I mean, I think that is a fair question… We are facing sort of an optics issue, I think."

Mansour said the advisory relationship predated the 2026 election and was not political, telling MS Now, "The key thing is we did it before the election. It is not a political decision, and it still isn't."

What does Polymarket have to do with this?

Trump Jr. remains tied to Polymarket both as a partner at 1789 Capital and as an adviser to that platform. The firm's $300 million investment in Polymarket was reported in August 2026, building on a smaller stake it took in August 2025, according to Ars Technica.

What happens next?

No new regulatory action was announced alongside the advisory split, and neither company detailed further changes to Trump Jr.'s role going forward, based on current reporting. Readers following the prediction-market fight between the two platforms can track developments through the originating Ars Technica report.