O impacto dos pareceres de auditoria na variação do preço (retorno) das ações preferenciais das empresas listadas na Bovespa

Abstract

The globalization of the economy has been characterized by the breakdown of trade barriers between countries and the increase of foreign investments in the capital markets. Allied to this whole process of changing societies, the responsibility for accounting information became more relevant and essential due to financial scandals involving several companies in the world which triggered a growing concern of various stakeholders in quality, reliability and transparency of accounting information. This study seeks to verify how the price (return) of actions react to the disclosure of audit opinions. Firstly a literature review on the concepts and objectives of the audit has been made, its historical development, standards, regulations and their bodies, and the nature of the audit opinions. Regarding to the methodology used in this work, are considered the bibliographic searches, documentary and secondary data collecting. First a literature search has been taken that included among other resources, scientific production, national standards, published papers in conferences, etc. The documental research was compiled from the review of audit opinions for the selected companies were taken from the site of the Securities Commission. The purpose of this verification was to observe each of the selected companies if their audit opinions were issued with or without exception. The secondary datas were taken through the disclosure of the shares traded on the Stock Exchange by the Economatica System. From these data it was calculated the average of the shares 30 days before and 30 days after the publication of opinions. Then it was used the Wilcoxon test in order to compare the average price action before and after the release of opinion. Thus it was possible to identify the years in which the opinion had any influence on stock price. Then the overall average return was calculated separately for firms with and without exception in their opinions in order to obtain an average return for all the companies in those categories. Thus we can conclude, based on the results of the tests performed, that the publication of audit opinions seems not to have influenced the average value of the shares in the month after its release in most years that it has been studied.