Donald Trump Jr. ends Kalshi advisory rolePolitico reports that Kalshi says it and Donald Trump Jr. mutually agreed to end his advisory role, attributing the split to his firm 1789 Capital's roughly $300 million investment in Kalshi's rival Polymarket. He had joined Kalshi as an adviser in 2025 and later Polymarket, and his exit comes as Democrats prepare to target Trump-family-backed companies.