Baltimore Takes Legal Offensive Against Prediction Markets and Major Crypto Platforms

Mayor Brandon Scott and the Baltimore City Council filed suit against Kalshi and Polymarket, dragging Coinbase, Robinhood, and Webull into the crosshairs over what they're calling illegal sports betting operations.

The lawsuit represents an escalating regulatory push against crypto-native prediction markets that have grown increasingly popular among retail traders. Baltimore's legal challenge targets not just the platforms facilitating these bets, but also the major trading infrastructure providers enabling access to them.

The Core Complaint

The city alleges that Kalshi and Polymarket are operating illegal gambling operations by allowing Baltimore residents to place wagers on sports outcomes without proper licensing. By naming Coinbase, Robinhood, and Webull—three of crypto's biggest on-ramps for retail investors—Baltimore is essentially arguing that these mainstream brokers are complicit in distributing access to unlicensed betting platforms.

This strategy mirrors how regulators have previously targeted payment processors and banking partners of crypto exchanges. It's an indirect but potentially more effective pressure point: make it harder for users to fund illegal activity through mainstream channels.

Prediction Markets Under Siege

Kalshi and Polymarket have operated in a regulatory gray zone. Both platforms allow users to trade contracts tied to real-world outcomes—from election results to sports scores. They argue these are binary options markets, not traditional gambling, a distinction that hasn't protected them from legal scrutiny in most U.S. jurisdictions.

Polymarket, built on Ethereum and leveraging the crypto stack for settlement, has seen explosive growth in recent cycles. The platform has become particularly popular for political betting, drawing significant volume during major election cycles. Kalshi operates similarly but has positioned itself more aggressively toward U.S. compliance, claiming regulatory clearance for certain types of event contracts.

Why This Matters for Crypto Infrastructure

Baltimore's approach is instructive for anyone tracking regulatory evolution in crypto. Rather than targeting just the protocol or decentralized platform, the city is holding trading platforms and brokers accountable for their user base. This puts pressure on mainstream financial infrastructure providers—Coinbase, Robinhood, Webull—who have built their entire business models on retail accessibility.

The three platforms face a decision: continue facilitating transfers to prediction markets and face state-level litigation, or begin restricting access. Neither option is attractive. Blocking transactions raises censorship concerns; complying with every municipal lawsuit sets a troubling precedent for regulatory fragmentation.