Impacto ambiental e retorno acionário de companhias listadas na BM&FBOVESPA

Abstract

This study aimed to analyze if the information from an environmental incident causes impact on stock prices of the companies responsible, indirectly analyzing the loss of informational efficiency semi-strong level. For this, the event studies methodology was used together with a bootstrap simulation. Data from daily prices of assets were collected from Bloomberg® software and the news of environmental disasters were collected in newspaper advertisements. The events are summarized in the mining and oil sector companies listed on BM&FBovespa. The results suggest evidence of loss of efficiency for events in general, and that share prices suffered falling within 4 days after the event. Thus market efficiency did not behaved semi-strong form, the delay in the incorporation of this information. Our research suggests a need for increased credibility in the dissemination of information to the market, as investors cautiously observe the effects of these events in stock prices.