MLB announced a partnership with Polymarket on Thursday that includes integrity monitoring, data sharing and the right to use intellectual property. But the bulk of the agreement doesn’t cover that Polymarket.
It’s focused on Polymarket’s yet to be fully launched U.S. prediction market exchange, rather than Polymarket’s separate crypto-based international exchange, for which the company is widely known.
While MLB has touted the agreement as necessary to enhance integrity standards in prediction markets, giving it the right to “restrict markets that present an integrity risk,” this provision has limited meaning right now. Polymarket’s much-larger international exchange is not subject to the same terms of the deal.
To get a sense of how tiny Polymarket’s U.S. product is currently, its notional betting volume in 2026 is about $700 million, compared with about $20 billion for the company’s international exchange. Kalshi, a Polymarket competitor, recorded $3 billion in notional volume last week alone (Kalshi has one exchange, which is U.S.-based but also takes bets in some other countries).
Notional volume on Polymarket U.S. actually decreased from January to February.
Polymarket’s branding, which MLB will use, is the same for its U.S. and international units. The international exchange is where bets on military strikes are listed, which has drawn the ire of U.S. lawmakers. It also facilitated bets on whether sex toys would be thrown on WNBA courts last year. And the product does not ask users to provide personal identification before placing bets—a requirement for U.S.-based exchanges meant to guard against bad actors.
U.S. authorities have no control of Polymarket’s international exchange; the Commodity Futures Trading Commission (CFTC) only oversees the registered U.S. product, along with prediction market exchanges such as those owned by Kalshi and Crypto.com.
Polymarket’s international rulebook says people in the U.S. are not permitted to place bets, and the exchange blocks bettors recognized as having U.S. IP addresses, keeping it out of the purview of the CFTC. But Americans can easily circumvent the IP address ban through inexpensive VPNs that mask their location.
MLB and the CFTC announced a memorandum of understanding Thursday “to discuss, cooperate, and exchange information concerning issues of common interest, such as the integrity of professional baseball” through “ongoing, informal consultations, as well as periodic meetings, written requests as needed, and other practical arrangements.”
Again, this doesn’t apply to the more widely used international Polymarket product.
Polymarket, which also has an exclusive licensing deal with MLS and a non-exclusive agreement with the NHL, did not respond to a request for comment. MLB declined to comment.
(In January, Polymarket was among the sponsors of the Golden Globes, which is part-owned by Sportico parent Penske Media.)
