AmEx Wins Antitrust Case on Merchant Rules

American Express Inc. prevailed June 25 when the U.S. Supreme Court agreed with its argument that rules about how merchants should treat cardholders don’t violate antitrust laws.

In a 5-4 opinion, the justices held that the plaintiffs, several U.S. attorneys general, didn’t show anticompetitive effects from AmEx’s rules forbidding merchants to steer customers to credit cards that charge a lower swipe fee than AmEx.

The Justice Department originally sued in 2010, arguing that the practice was anticompetitive. A district court agreed in 2015, but the U.S. Court of Appeals for the Second Circuit reversed in 2016, saying the DOJ hadn’t ...