Petroleo Brasileiro S.A. – Petrobras v. Universities Superannuation Scheme Limited

Issues: (1) Whether the legal standard to invoke Basic Inc. v. Levinson's presumption of reliance at minimum requires empirical evidence that a security generally reacted in a directionally appropriate manner to new material information—that its price went up on good news and down on bad news—or, as the U.S. Court of Appeals for the 2nd Circuit ruled, whether the presumption can be based on other factors entirely unrelated to whether the alleged misstatement had price impact notwithstanding the Supreme Court's holding in Halliburton Co. v. Erica P. John Fund, Inc. (Halliburton II); and (2) whether, contrary to the U.S. Court of Appeals for the 2nd Circuit's ruling below, Federal Rule of Civil Procedure 23 and due process require that class membership be ascertainable through administratively feasible means.