This paper examines the effects of a common stock repurchase on the values of the repurchasing firm's common stock, debt and preferred stock, and attempts to identify the dominant factors underlying the observed value changes. The evidence indicates that significant increases in firm values occur within one day of a stock repurchase announcement. These value changes appear to be due principally to an information signal from the repurchasing firm. Common stockholders are the beneficiaries of virtually all of the value increments, but no class of securities examined declines in value as a result of the repurchase.