Testing market efficiency: empirical investigation of polish capital market

The aim of the work is to verify the hypothesis of a weak form of efficiency of the Polish capital market using the autocorrelation test, series and variance ratio test. The research was conducted for the entire market representing the Warsaw Stock Exchange (using the WIG index covering all companies listed on the Main Market of the Warsaw Stock Exchange) and selected sector sub-indices of the WIG index calculated by the stock exchange. The analyzes were based on the daily logarithmic rates of return for data from the 2010-2016 period, which was divided into three sub-periods. The results indicate a weak form of market efficiency and cases of inefficiencies in its sectors