Planos de estabilização e instabilidade nos mercados acionários

Abstract

The role of stock market indices is explained with a description of the major stock exchange indices found in various countries, as uiell as with a discussion of index computation methodologies. The series (January 1968 to February 1991) of real changes in the São Paulo Stock Exchange lndex is described, tested for normality, and examined for changes in the morerecent period, marked by economic stabilization plans. The results herein reported show that the market has become more unstable, and that the process of risk reduction through portfolio diversification has been adverselyaffected, with the adoption of the so-called stabilization plans: existing risks have increased and new types of risk appear to have been introduced.