The following post is reprinted with permission from Paul Karlsgodt’s blog, Stay tuned over the coming days for more in-depth analysis of the Amgen decision and its potential implications for securities class actions and class actions more generally.

The Supreme Court has issued its opinion in one of the most highly anticipated class action-related cases on the docket this term. The result in Amgen Inc. v. Connecticut Retirement Plans and Trust Funds, No. 11-1085, slip op. (U.S., Feb. 27, 2013) is not surprising given the content and tone of the questioning at oral argument. In an 6-3 opinion authored by Justice Ginsberg, the Court held that the plaintiff in a securities fraud case based on a fraud-on-the-market theory of reliance does not have to prove materiality of the fraudulent statement or omission at the class certification stage. Because materiality is a common question capable of resolution simultaneously for the entire class, the majority reasoned, it does not have to be proven at the class certification stage. Justices Scalia, Thomas, and Kennedy dissented.

Amgen is an important decision in the securities fraud context because it addresses the lingering question of whether any special prerequisites exist in certifying a securities fraud class action that aren’t required in certifying other types of class actions. Like the Supreme Court’s earlier decision in Erica P. John Fund v. Halliburton Co., 131 S. Ct. 2179 (2011), Amgen will probably have an impact beyond the securities fraud context. In the context of class certification decisions more broadly, the opinion will be almost certainly be cited as clarifying the distinction between issues impacting the elements of class certification, which must be resolved at the class certification phase, and merits issues, which can wait until trial to be resolved.