Weeks ago, the U.S. Supreme Court decided Lamps Plus v. Varela, No. 17-988 (April 24, 2019), another in a series of decisions upholding, under the Federal Arbitration Act, agreements to arbitrate individual disputes and denying class arbitration unless the contract clearly and explicitly provides for class proceedings. In a case nearly a decade earlier, Stolt-Nielsen S.A. v. AnimalFeeds Int’l, 559 U.S. 662 (2010), the court held that arbitration may not be compelled on a class-wide basis when an agreement is “silent” on such availability.

In the new Lamps Plus ruling, the court holds that an arbitration agreement that is ambiguous on whether class arbitration is authorized likewise does not permit courts to infer that class-wide arbitration was agreed to. In the words of the court majority: “Like silence, ambiguity does not provide a sufficient basis to conclude that parties to an arbitration agreement agreed to ‘sacrifice the principal advantage of arbitration.’”