Law360, New York (August 30, 2012, 1:39 PM ET) -- One of the key stages in many securities class actions is class certification. The most common path for plaintiffs to obtain certification includes showing that the market in which the securities at issue traded was efficient, leading to what, in 1988, the U.S. Supreme Court in Basic v. Levinson, 485 U.S. 224 (1988) termed a “rebuttable presumption” of reliance common to all class members.
The following year, in Cammer v. Bloom, 711 F. Supp. 1264, 1285-87 (D.N.J. 1989), Judge Alfred J. Lechner listed five factors that...