MLB maintains restrictions on player betting activity

Major League Baseball told players that involvement in prediction markets tied to baseball outcomes is a violation of its betting rules, according to a memo distributed during the 2025 season.

The August 26 memo, titled “Re: Baseball Related Prediction Markets,” was sent jointly by commissioner Rob Manfred’s office and the MLB Players Association.

It stated that “participating in ‘prediction markets’ to risk money on any outcome related to baseball games or events” is prohibited. The document identified several companies offering such markets, noting: “Several companies (including Kalshi, Robinhood, and Crypto.com, among others) are now offering what they call ‘prediction markets,’ which allow members of the public to risk money on the outcome of specific events, including baseball and other sporting events.”

The communication was circulated across Major and Minor League Baseball and posted near locker rooms. Some players later told Front Office Sports they had not yet been informed of the policy notice.

MLB said reference markets involving baseball “recently came to our attention.” Records show Kalshi began offering MLB markets on April 16, more than four months before the memo was issued.

MLB did not answer questions on when it first learned of baseball-related contracts or whether players who traded earlier in the season could face discipline. The MLBPA declined to comment.

Industry debate over market classification

Prediction market operators maintain they are not gambling companies, a distinction backed by federal regulators. Their contracts are available in jurisdictions where wagering on sports is not legal. That difference has led to contrasting stances from the major professional leagues.

The National Hockey League has marketing agreements with Kalshi and Polymarket. The NFL has stated its concern about limited regulatory oversight and that the offerings “mimic sports betting.” The NBA is addressing an ongoing investigation involving a player, a coach, and a former league member in a gambling case. In May, NBA assistant general counsel Alexandra Roth requested “specific regulatory provisions that can mitigate the associated integrity risks” in a letter to the Commodity Futures Trading Commission.

Regulatory posture in Washington shifted after Polymarket was banned in the United States during the Biden administration, only to relaunch under the current administration. Kalshi earlier took legal action against the CFTC regarding election-based products, winning a ruling that the agency later stopped contesting.

Leagues cite integrity and data access concerns

MLB vice president Bryan Seeley wrote in March to the CFTC that integrity protections under federal rules are insufficient. “As the resemblance between sports event contracts and traditional sports betting markets continues to grow, so too does the need to replicate the integrity and consumer protections that exist at the state level,” Seeley said. He added that reporting of suspicious activity is not guaranteed and that some exchanges believe they are restricted from sharing information with leagues.

Data alerts have previously contributed to investigations such as the case involving Cleveland Guardians pitcher Luis Ortiz, who, along with teammate Emmanuel Clase, was charged with wire fraud conspiracy and remains on leave.

State regulatory actions and licensing issues

While federal regulators have allowed the markets to operate, several states have signaled enforcement plans. Michigan’s Gaming Control Board noted that involvement in sports-related event contracts “will have implications relative to your licensure in Michigan.” Nevada regulators said offering such contracts “constitutes wagering,” and violations could risk an operator’s license.

Legal challenges are active in New Jersey, Maryland, California, and Massachusetts. Arizona, Ohio, and Pennsylvania have also issued warnings to operators.

For MLB, the internal policy provides a clear boundary for players as the legal and commercial environment shifts. The league continues to partner with major sportsbooks, such as DraftKings and FanDuel, but has not entered into similar arrangements with prediction market platforms like Kalshi or Polymarket.