A class period is a range of dates within which a company is alleged to have been engaged in improper conduct. The attorneys investigating and prosecuting a case will review the facts of the case, and along with the court-appointed Lead Plaintiff, determine the appropriate beginning and end of a class period. Sometimes, after an initial complaint is filed, a class period will be lengthened or shortened as an investigation continues. If you purchased the securities of a company during a class period, you are automatically a class member, regardless of whether you specifically retain a law firm to prosecute claims on your behalf. This class membership concept is also true with respect to consumer fraud class actions and antitrust class actions. For example, if you purchased goods from a company that was accused of improper marketing practices during the relevant period of time (the class period), you would be a member of the class for a consumer fraud class action, even if you did not personally retain an attorney.