Bricklayers & Trowel Trades Intern. v. CSFB

This opinion first explains the basics of event studies, and their importance in securities litigation. The court then discusses problems with the particular study performed by plaintiffs' main expert witness. In this rare case, the court grants defendants' motion to exclude plaintiffs' expert testimony as misleading, which here further leads the court to grant summary judgment for the defendant sua sponte. For a different take on the analysis performed by the expert, see the plaintiffs' brief.