Republican Sen. John Curtis of Utah has asked Senate Judiciary Committee leaders to investigate business activities involving members of presidential families, with his request covering Donald Trump Jr. and Hunter Biden.
Curtis sent a letter dated September 21 to Judiciary Committee Chair Chuck Grassley and Ranking Member Dick Durbin asking the panel to examine whether presidential family relationships have provided private financial benefits or preferential access. He also urged the committee to subpoena Trump Jr. and Biden over previous business dealings, relationships with foreign individuals and entities, and benefits they have received.
The Utah senator presented the request as an issue of congressional oversight that should apply regardless of political affiliation. His concerns surrounding Trump Jr. include the president’s son’s connections to prediction market operators Kalshi and Polymarket, whose activities remain at the center of regulatory and legal disputes involving federal oversight.
“I urge the Committee to subpoena Donald Trump Jr. and Hunter Biden to testify regarding their past business dealings, relationships with foreign individuals and entities, gifts, or other benefits they have received, and any instances in which their relationship to the President was invoked or understood to provide value,” Curtis wrote.
Curtis Raises Questions Over Business Relationships
Curtis cited Hunter Biden’s past business interests involving foreign entities in China and Ukraine while discussing the need for further scrutiny. His letter also focused on Trump Jr.’s business relationships and benefits he has reportedly received.
Among the matters Curtis highlighted was Russian businessman Umar Kremlev’s reported role in covering a substantial portion of expenses connected with a three-day celebration following Trump Jr.’s wedding in the Bahamas. Curtis also referred to Trump Jr.’s involvement in family-backed cryptocurrency ventures and international real estate deals. His letter mentioned reported investments involving defense contracting as well.
Curtis linked the proposed investigation to concerns about public confidence in government. He cited data from the Partnership for Public Service showing that 27% of Americans trust the federal government, while 72% described it as “corrupt.”
“These reports raise legitimate questions about foreign access to members of a sitting president’s family and whether such relationships can create actual or perceived expectations of favorable treatment,” Curtis wrote. “They also may create expectations of a returned favor that would not be in the best interests of the American people or our allies, and could even create national security vulnerabilities.”
Hunter Biden responded publicly to the proposal and said he would testify before Congress without requiring a subpoena. He referred to more than seven hours of sworn testimony he previously provided and denied having foreign business dealings while his father served as president.
Grassley said he would review Curtis’s request with Judiciary Committee staff. Committee members John Cornyn of Texas and Thom Tillis of North Carolina also expressed support for pursuing the matter.
Trump Jr.’s Kalshi and Polymarket Connections
Curtis gave particular attention to Trump Jr.’s involvement with prediction markets because the companies operate within a sector facing significant questions over the division of federal and state regulatory authority.
Trump Jr. holds a paid advisory position with Kalshi and received equity when he joined the company. He also advises Polymarket and works as a partner at 1789 Capital. The investment firm committed $300 million to a recent Polymarket funding round, making it one of the company’s largest equity holders.
“This pattern extends to [Donald Trump Jr.’s] significant financial and advisory ties to prediction market platforms that depend on favorable federal regulatory decisions being considered by the Commodity Futures Trading Commission,” Curtis wrote, according to SBC Americas.
Trump Jr. spokesman Andrew Surabian has said Trump Jr. does not trade on prediction markets and does not communicate with the federal government on behalf of Kalshi or Polymarket. Surabian has described Trump Jr.’s work with the companies as marketing advice and argued that he remains entitled to conduct outside business as a private citizen while his father serves as president.
The Trump family’s involvement with the sector also extends to Trump Media & Technology Group. The company announced plans in 2025 for Truth Predict, a cryptocurrency-based prediction market product intended for Truth Social through a planned relationship with Crypto.com.
The proposed service has not developed into the broad standalone prediction market platform originally described. Trump Media instead moved forward with a marketing arrangement involving Crypto.com.
Legal Disputes Add to Prediction Market Scrutiny
The investigation request comes as Curtis’s home state remains involved in its own legal dispute over prediction market sports contracts.
Utah officials argue that Kalshi’s sports contracts constitute illegal wagering under state law. Kalshi maintains that the Commodity Exchange Act places its event contracts under federal regulation through the Commodity Futures Trading Commission and prevents Utah from applying state gambling restrictions to those products.
Gov. Spencer Cox announced earlier in 2026 that Utah intended to challenge prediction markets and the CFTC. Kalshi subsequently sued the state.
In September, the Tenth Circuit Court of Appeals denied Kalshi’s emergency motion seeking an injunction while its appeal continues. The ruling allows Utah to enforce its gambling laws during the ongoing litigation.
Federal appeals courts have reached differing conclusions in other prediction market cases. The Third Circuit supported Kalshi’s federal preemption argument in its dispute involving New Jersey. The Ninth Circuit reached a different conclusion in litigation involving Nevada and California tribal lands, finding grounds for state or federal gaming laws to apply to sports event contracts despite arguments based on CFTC jurisdiction.
New Jersey has asked the U.S. Supreme Court to address the disagreement among federal appellate courts. Robinhood and Crypto.com have also submitted similar petitions.
The ongoing cases place the regulatory status of prediction markets before courts at the same time Curtis is seeking congressional scrutiny of Trump Jr.’s financial and advisory connections to two major companies operating in the sector.