The option pricing model and the risk factor of stock

In this paper a combined capital asset pricing model and option pricing model is considered and then applied to the derivation of equity's value and its systematic risk. In the first section we develop the two models and present some newly found properties of the option pricing model. The second section is concerned with the effects of these properties on the securityholders of firms with less than perfect 'me first' rules. We show how unanticipated changes in firm capital and asset structures can differentially affect the firm's debt and equity. In the final section of the paper we consider a number of theoretical and empirical implications of the joint model. These include investment policy as well as the causes and effects of non-stationarity in the systematic risk of levered equity and risky debt.