Amgen Inc. v. Connecticut Retirement Plans and Trust Funds — Scalia, J., Dissenting

Summary

Justice Scalia dissents, arguing that a plaintiff invoking the fraud-on-the-market presumption to establish commonality at class certification must prove materiality at that stage, as materiality is a predicate to the presumption and reliance. He contends *Basic Inc. v. Levinson* intended the presumption to apply to certification, and the Court's contrary holding expands the consequences of Basic unnecessarily. Justice Thomas dissenting (joined by Kennedy) agrees materiality is a condition precedent to certification. Justice Alito concurred, noting reconsideration of the Basic presumption may be appropriate.