Law Commons^™

Power And Statistical Significance In Securities Fraud Litigation, Jill E. Fisch, Jonah B. Gelbach

All Faculty Scholarship

Event studies, a half-century-old approach to measuring the effect of events on stock prices, are now ubiquitous in securities fraud litigation. In determining whether the event study demonstrates a price effect, expert witnesses typically base their conclusion on whether the results are statistically significant at the 95% confidence level, a threshold that is drawn from the academic literature. As a positive matter, this represents a disconnect with legal standards of proof. As a normative matter, it may reduce enforcement of fraud claims because litigation event studies typically involve quite low statistical power even for large-scale frauds.

This paper, written for …

The Logic And Limits Of Event Studies In Securities Fraud Litigation, Jill E. Fisch, Jonah B. Gelbach, Jonathan Klick

All Faculty Scholarship

Event studies have become increasingly important in securities fraud litigation after the Supreme Court’s decision in Halliburton II. Litigants have used event study methodology, which empirically analyzes the relationship between the disclosure of corporate information and the issuer’s stock price, to provide evidence in the evaluation of key elements of federal securities fraud, including materiality, reliance, causation, and damages. As the use of event studies grows and they increasingly serve a gatekeeping function in determining whether litigation will proceed beyond a preliminary stage, it will be critical for courts to use them correctly.

This Article explores an array of …

Economic Crisis And The Integration Of Law And Finance: The Impact Of Volatility Spikes, Edward G. Fox, Merritt B. Fox, Ronald J. Gilson

Faculty Scholarship

The 2008 financial crisis raised puzzles important for understanding how the capital market prices common stocks and in turn, for the intersection between law and finance. During the crisis, there was a dramatic fivefold spike, across all industries, in "idiosyncratic risk" – the volatility of individual-firm share prices after adjustment for movements in the market as a whole.

This phenomenon is not limited to the most recent financial crisis.This Article uses an empirical review to show that a dramatic spike in idiosyncratic risk has occurred with every major downturn from the 1920s through the recent financial crisis. It canvasses three …

The Sec And The Madoff Scandal: Three Narratives In Search Of A Story, Donald C. Langevoort

Georgetown Law Faculty Publications and Other Works

This essay, part of a symposium on narrative in corporate law, considers various portrayals of the complicity of the SEC in the Bernard Madoff scandal--including the Commission's own Inspector General's report issued in September 2009. It considers possible explanations (revolving door problems, incompetence and sloth, etc.) but suggests that the story is deeper and more frustrating, arising out of the relative poverty in which the SEC operates, which in turn leads to habits of thought and action that leave too much unnoticed and undone. The interesting question, then: why the poverty? The essay concludes with a political explanation. While by …