Efficient Market Hypothesis and Market Anomalies of LQ 45 Index in Indonesia Stock Exchange

The paper attempts to investigate the validity of the Efficient Market Hypothesis and the existence of calendar effect on Indonesia Stock Exchange Market. Initially, this paper discusses types of EMH also the literature available regarding this topic. The sample of research is twenty one securities listed in LQ 45 Index on the Indonesia Stock Exchange Market (IDX), this paper applies non parametric tests which are Run test, Kruskal-Wallis test, Mann-Whitney test  parametric test which are series correlation test, One-way Anova test and independent t-test two sample. Based on the results of the test of this paper, it can be concluded that Weak Form Efficient Market exists in LQ 45 Index of IDX while Day of the Week Effect and Month of the Year Effect are not found to exist in LQ 45 Index of IDX. In conclusion, it is observed that the effect of stock prices for the sample companies on future prices is very meager and an investor cannot reap profits by using the historical share price data as the current share prices already reflect the effect of past share prices data.