Testing efficient market hypothesis with MS-GARCH models

Abstract

An attempt was made to verify the impact of employee stock options (ESO) on the financial situation of companies and the effects observed in the changes of the stock price. The research consisted of a comparative analysis of the conditions of banks that implemented ESOs and those that did not. Subsequent analysis covered a wider group of companies from different branches of the economy that implemented motivational schemes, according to the effects the options had on their situation. Based on the conclusions of these analyses, another research project based on the MS-GARCH models was made for the stock price time series to verify the efficient market hypothesis according to the implementation and exercise of the ESOs.