Federal antitrust enforcers say competing casino hotels illegally colluded to set room rates by knowingly adopting the same algorithmic pricing platform, a tacit agreement that amounts to an antitrust violation, even if the hotels never communicated directly.

The Federal Trade Commission and Department of Justice filed a statement of interest late Thursday in Cornish-Adebiyi v. Caesars Entertainment, where a class of New Jersey hotel guests claim they paid “supracompetitive” prices for rooms at Caesars Atlantic City Hotel & Casino and the Hard Rock Hotel & Casino Atlantic City. The suit, filed in May 2023, says the prices were driven by an algorithmic pricing platform called Rainmaker that analyzes real-time data about market supply and demand to generate “optimal” room rates.