Deadline Arrives For Leagues, NCAA To Disclose Gambling, Prediction Markets Ties To Sen. Blumenthal

May 1st, 2026 11:14 AM EDT

Friday marks the deadline for five major pro sports leagues and the NCAA to disclose details about their sports betting, prediction market, and data provider relationships.

Individual letters were emailed to the NFL, NBA, NCAA, MLB, NHL and MLS from Sen. Richard Blumenthal (D-Conn,) on April 9. The letters sought information on how each body works to address integrity risks, problem gambling and athlete safety.

The NHL, NBA, and MLS told Bookies.com this week that they have or planned to respond to the queries. There was no word from the MLB, NFL, or NCAA. Bookies.com requested comment from Blumenthal's office.

Seeks Details On All Betting Relationships

While each letter sought specifics from organizations given their publicly known relationships, the basic format and focus remains the same.

Blumenthal warned that legalized sports betting — following the 2018 PASPA decision — has become deeply embedded across the sports landscape. In his view, that growth has brought a surge in gambling-related harms, including addiction concerns, threats directed at players and potential risks to the integrity of competition.

The senator took aim at prediction markets, where users trade contracts tied to the outcomes of events, including games. Those platforms, like Kalshi and Polymarket U.S., fall under the oversight of the Commodies Futures Trading Commission, not state gaming regulators. Blumenthal argues the rapid rise of these platforms further complicates oversight and existing betting integrity issues.

Blumenthal asked leagues to disclose all betting-related partnerships, outline the data shared with operators, and clarify wager limits.

He noted shifting fan behavior, with some spectators increasingly focused on their own betting outcome rather than team wins or losses. He claims this trend risks reducing athletes to commodities and puts their well-being under added scrutiny.

Leagues Enjoy Extensive Betting, Prediction Market Ties

The NBA partners with multiple betting operators (see above). FanDuel remains an official odds provider for NBA and WNBA games that stream on Prime Video. And it offers viewers who opt-in a personalized bet tracking experience.

Several sportsbooks that partnered with the NFL let their deals lapse due to cost concerns over data sharing. However, one major sports betting operator tells Bookies.com that they expect to have a deal with the NFL - at least when it comes to data sharing - before the season begins.

Thus far, MLB, the NHL and MLS have all partnered with prediction markets.

NHL Commissioner Gary Bettman On Prediction Markets

"We are very comfortable with the safeguards to be built into our contracts with respect to our ability to control for the security," Commissioner Gary Bettman said Tuesday. He spoke to a group from the Associated Press Sports Editors at the league's headquarters in New York.

"You have to acknowledge the things that are going on around you. And first of all, if there was going to be prediction contracts, we wanted them based on your back for the benefit of our fans. But secondly, and most importantly, we have the ability to knock out any prediction contracts we don't think are appropriate, which gives us more control," Bettman said Tuesday. "And we are monitoring that market in real-time. So that in the event an contract is the one that we don't think is appropriate, we can envision the reasons we might not think it was appropriate. We can make them take it out."

Has that happened yet?

"Hasn't happened. It's really the prop betting where this comes up, whether it's sports betting or the prediction market. And our game isn't as susceptible as the other games. So in terms of being comfortable, in terms of the integrity of the game and our people, I have complete confidence in our players and our office personnel. But more than that, the game doesn't lend itself to some of the issues."

MLS Commissioner Don Garber On Prediction Markets

"We think about these things all the time. I obviously paid close attention to the recent deal announced by Rob (Manfred) and Major League Baseball. We'd rather be in it. And be able to have influence on governance and about checks and balances, than be on the outside and be victimized by things we have no control over. Predictive markets exist. Sports betting exists. My view, and I think all the commissioners feel the same way. It's not about generating revenue. It's about having a sense of control and being able to influence how these businesses are operating. And I think we've been very effective at that.," Garber said. "I feel no differently about prediction markets than I do about sports betting. And it's been new for us. We haven't had any issues, but you're all following sports. Do I think there'll be issues at some point? I'm sure there will be. And we, our chief counsel, along with the other leagues, are involved in ensuring that that memorandum could be something that'll be effective."

Prediction Markets Face Intensifying Scrutiny After Insider-Trading Case

Prediction markets are drawing renewed scrutiny after a series of questionable trades tied to geopolitical events, including U.S. actions in Venezuela and escalating tensions involving Iran.

At the center of the latest controversy is U.S. soldier Gannon Ken Van Dyke, who prosecutors say used classified information to profit on trades placed through Polymarket. Authorities allege Van Dyke netted roughly $409,000 by wagering on the timing and outcome of a U.S. military operation targeting Venezuelan leader Nicolás Maduro.

The U.S. Department of Justice last week charged Van Dyke with multiple offenses. The included misuse of confidential government information, commodities fraud, wire fraud and unlawful financial transactions. The case is believed to be the first U.S. criminal prosecution tied directly to insider trading on a prediction market.

The allegations have added fuel to a growing debate in Washington over how — or whether — to regulate these platforms. Lawmakers from both parties have introduced proposals aimed at tightening oversight and criminal enforcement.

One such proposal, the DEATH BETS Act (H.R. 7942) and its Senate counterpart, would bar any CFTC-regulated exchange from offering contracts linked to terrorism, assassination, armed conflict or an individual’s death.

Read Each Letter Here:

Here is each letter sent by Blumenthal:

Blumenthal Letter Download