Kalshi, the nation’s leading prediction market, said on Thursday that Donald Trump Jr., the president’s eldest son, would no longer serve as an adviser.

The firm’s officials said in a statement that they and Donald Trump Jr. had agreed to part ways because his investment firm, 1789, had heavily invested in Polymarket, Kalshi’s biggest competitor. A spokesman for Donald Trump Jr. confirmed that the decision was mutual.

It was not immediately clear whether the president’s oldest son would keep the shares in Kalshi given to him as part of his compensation package when it hired him in January 2025. Those assets are now estimated to be worth millions.

Kalshi said it reached out to Donald Trump Jr. this fall to discuss ending his contract after 1789, in August, added about $300 million to its investments in Polymarket on top of its earlier contributions of about $200 million.