Today, the Supreme Court agreed to hear an appeal involving certification of securities fraud class actions. The case, Amgen Inc. v. Connecticut Retirement Plans and Trust Funds, No. 11-1085, --- S. Ct. ----, 2012 WL 692881 (June 11, 2012), presents two questions: (1) whether, in a misrepresentation case under Section 10(b) of the Securities Exchange Act of 1934 and SEC Rule 10b-5, the district court must require proof of materiality before certifying a plaintiff class based on the fraud-on-the-market theory; and (2) whether, in such a case, the district court must allow the defendant to present evidence rebutting the applicability of the fraud-on-the-market theory before certifying a plaintiff class based on that theory.

In the decision below that is on appeal, the Ninth Circuit answered “no” to both questions. But other circuits have answered “yes” in other cases. The circuit-split means that, at present, defendants are being treated differently in different parts of the country.