Donald Trump Jr. agreed to end his advisory role with the prediction market Kalshi shortly after Trump Jr.’s venture capital firm made a large investment in its competitor, Polymarket.
“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,” Kalshi said in a statement provided to Ars and other news outlets this week.
Trump Jr. may still have a financial interest in Kalshi, which has benefited from the Trump administration’s legal and regulatory support for prediction markets. Trump Jr. “was handed about $300,000 worth of equity in Kalshi after joining the prediction market platform as a strategic adviser in early 2025,” the Financial Times reported in June .
“Kalshi’s donation of shares to the US president’s eldest son granted him a stake in the private company when it was valued at under $2 billion, less than a tenth of its $22 billion valuation in a funding round last month,” the Financial Times article said. Kalshi is reportedly in talks for a new funding round that would value it at $65 billion.
Trump Jr. simultaneously has an interest in Polymarket via his role as a partner at 1789 Capital and as an advisor for Polymarket. The venture firm’s investment of $300 million in Polymarket was reported in August 2026 , building on a smaller investment it made in Polymarket in August 2025 .
“We have been discussing this internally since August when news of 1789’s investment in Polymarket became public,” a Kalshi spokesperson said. “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 Trump administration has helped prediction markets grow with a permissive regulatory approach taken by the Commodity Futures Exchange Commission (CFTC). The CFTC has also sued 11 states in attempts to block state regulation of prediction markets, and filed briefs supporting Kalshi in its own cases against individual states. Attorneys general in many states accuse Kalshi of running an illegal gambling operation.
