ABSTRACT We examine empirical implications of models of differential information that formalize the following intuition: securities for which there is relatively little information are perceived as relatively more risky because of the greater uncertainty surrounding the exact parameters of their return distributions. The implication that beta risk for low information firms should decline as information increases is confirmed with several data sets. We find such a decline over the first several periods subsequent to initial public offerings and initial listings. There is also an abrupt risk decline at the first annual earnings announcement.

The authors examine empirical implications of models of differential information that formalize the following intuition: securities for which there is relatively little information are perceived as relatively more risky because of the greater uncertainty surrounding the exact parameters of their return distributions. The implication that beta risk for low information firms should decline as information increases is confirmed with several data sets. The authors find such a decline over the first several periods subsequent to initial public offerings and initial listings. There is also an abrupt risk decline at the first annual earnings announcement.

We examine empirical implications of models of differential information that formalize the following intuition: securities for which there is relatively little information are perceived as relatively more risky because of the greater uncertainty surrounding the exact parameters of their return distributions. The implication that beta risk for low information firms should decline as information increases is confirmed with several data sets. We find such a decline over the first several periods subsequent to initial public offerings and initial listings. There is also an abrupt risk decline at the first annual earnings announcement.

THE PROBLEM of selecting a portfolio can be divided into two components: (1) the analysis of individual securities and (2) the selection of a portfolio or group of securities based on the previous analysis. Up to now, the majority of writers have focused on the first part of the problem and have developed several, well-accepted methods of analysis.1 Little attention has been paid to the second phase of the problem. It is to this second part of the portfolio selection process that this paper is principally devoted.