Public offer for shares acquisitions: evidence of value change in the financial market

Abstract

The market efficiency hypothesis in its semi-strong form, recommends the establishment of prices adjust instantly reflecting the public disclosure of all relevant information, restricting the opportunities for arbitrary abnormal returns. The aim of this study is to verify the occurrence of the variation of the stock price during the fixed-price self-tender offer, the Brazilian stock market between 2006 and 2015. The methodology used is the event study to assess the possibility of active abnormal returns relative to financial market. This research is distinguished by the number of takeover bids (65) occurred over a long period (10 years) studied, contributing through aggregation, to approximate the normal curve. Changes in the stock price were tested in the sprint, during and immediately after the event. The results were compared to fixed-price self-tender offer event, show that in most cases, is statistically significant change in the price of these parts. The conclusion is that there is evidence of the efficient market hypothesis in its semi-strong form during the study period, caused by the case of takeover bids, the Brazilian stock market.

Keywords

• Oferta Pública de Aquisição de Ações (OPA)
• Estudo de eventos
• Mercado eficiente.