증권집단소송에서의 피해액 추정

It is necessary to have the following two components to estimate aggregate damages in securities fraud class action: per-share inflation and total number of damaged shares. For the purpose of calculating accurate number of damaged shares, it is required to observe individual class member’s daily trading information: when and how many shares were bought/sold in each day of the class period. Unfortunately, this information is not observable in publicly available data. For this reason, plaintiffs’experts in the United States have relied upon certain methods of estimating the number of damaged shares: so-called“ plaintiff-style damages”analysis. This article purports to introduce various trading models used in that type of analysis, and to describe what kind of limitation should be placed upon in interpreting results obtained by running those models. In recent court decisions in the United States, the use of trading models, especially, proportional trading model (PTM) has been rejected as a scientific method to estimate aggregate damages in securities fraud class actions. Citing that the model(s) does not satisfy the so-called“ Daubert Standards,”the courts suggested of using actual claims data to obtain reliable estimates of the aggregate damages. While those rulings are theoretically sound and undisputable, the use of trading models should be valid in helping predict settlement amounts because the actual claims data are not available till later stage of the litigation. In that regard, studies of factors affecting settlements in securities fraud class actions are of another interest.