Kalshi Ends Donald Trump Jr. Advisory Contract After 1789 Capital Doubles Down on Polymarket

Kalshi, the US prediction market operator, has ended its advisory contract with Donald Trump Jr. after his venture capital firm 1789 Capital increased its stake in rival Polymarket, a Kalshi spokesperson told Reuters on 12 November 2026.

The split closes a relationship that began in January 2025 and ran in parallel with a second advisory role at Polymarket. It also lands as Democrats, who now control both houses of Congress according to Reuters, prepare to examine the Trump family's business ties and the prediction market sector.

What Kalshi said about the exit

Kalshi presented the departure as a joint decision driven by the competing investment. The spokesperson said: "We have mutually agreed to end Don's advisory role." The statement cited his firm's significant investment in a competitor "this past summer" and thanked him for helping Kalshi market to more customers.

The spokesperson told Reuters that talks on ending the contract started in August, after 1789 led Polymarket's most recent funding round. CoinDesk carried the same statement and the same "mutual" framing. When Reuters published, Trump Jr. and 1789 Capital had not commented, and Polymarket declined to comment.

A Reuters source said Trump Jr. was paid in equity for marketing guidance aimed at conservative audiences, including the MAGA movement. The Financial Times reported in 2025 that his Kalshi stake was worth $300,000, a figure that comes from press reporting rather than from Kalshi.

Timeline of Trump Jr.'s ties to both platforms

The Polymarket role came about seven months after the Kalshi appointment, so the two advisory relationships overlapped for roughly a year. Forbes, citing the Wall Street Journal, reported that the 2026 round followed an earlier $200m investment by 1789, which would make it one of Polymarket's largest backers. Both the Bloomberg and Forbes figures rest on unnamed sources, not company filings.

Political motive: two accounts

Kalshi's spokesperson told Reuters that the company never considered or discussed political implications. Two Reuters sources gave a different picture, saying some people inside Kalshi had raised concerns about the Democratic sweep and the congressional scrutiny that could follow. Reuters also reported that a source said Kalshi contacted Trump Jr. during the fall, which suggests the process ran for months rather than weeks.

The incoming Congress has already signaled its interests:

• Democrats have said they plan to use investigative powers on the Trump family's business ties, according to Reuters.
• Senator Elizabeth Warren has vowed to crack down on insider trading on prediction markets.
• Senator Chris Murphy and Representative Greg Casar introduced a bill earlier this year to ban prediction market bets on military operations and other sensitive government actions.
• Senator Catherine Cortez Masto and Representative Ro Khanna have criticized the Trump family's prediction-market stakes and the defense of sports contracts by the Commodity Futures Trading Commission (CFTC), the federal derivatives regulator. Khanna has called for a ban on those products, according to CoinDesk.

What it means for operators and partners

For Kalshi, the exit removes a high-profile adviser who was invested in its main competitor, just as the company expands its sports footprint. Recent Gamingo coverage shows how fast that footprint is growing: Kalshi was named the 76ers' official prediction market partner, and the CFTC signed a non-binding memorandum of understanding as the NBA picked Kalshi and Polymarket for league deals.

The commercial rivalry is also visible in demand data. Kalshi passed Polymarket in US search interest in October, as covered in Blask's October search figures.

State-level pressure continues in parallel. Ohio gaming licensees were told to cut ties with prediction markets, and Robinhood, Coinbase, Gemini and Moomoo agreed to halt Ohio sports event contracts. A Congress focused on conflicts of interest adds federal oversight risk to that state-level enforcement.

For sponsors, leagues and payment partners, the practical takeaway is that adviser and investor relationships across competing platforms are now a diligence item. Disclosure of equity-based advisory pay, cross-platform stakes and political ties may draw questions from committee staff once the new Congress convenes.

Status reviewed on 14 November 2026. Key figures come from Reuters, CoinDesk, Bloomberg and Forbes reporting plus Kalshi and Polymarket announcements. More business news and North America coverage.