On August 4, 2021, the Ninth Circuit voted to vacate a prior panel’s decision decertifying a class-certification order in an important multi-district antitrust case. The decision to rehear the case en banc was a disappointment for WLF, which filed an amicus brief in the case urging decertification. Pressing antitrust claims on behalf of three classes of purchasers of packaged tuna, the plaintiffs had to establish that common issues “predominate” within each class. The plaintiffs convinced the trial court to find such predominance, and grant class certification, based on an averaging of the alleged anticompetitive overcharges suffered within each proposed class. Although statistical or “representative” evidence—finding class-wide impact based on averaging assumptions and pooled transaction data—can be used to establish predominance, the district court abused its discretion here when it failed to resolve disputed questions of fact necessary to find predominance. WLF will monitor the en banc proceeding for any additional briefing opportunity.