Markowitz Model for Forming an Optimum Stocks Portfolio in The January Effect

This research aims to analyze the formation of an optimal portfolio using the Markowitz model for stocks listed in the LQ45 Index during the period from December 2022 to Jan 2024. The population of this research includes all 45 stocks in the LQ45 over this timeframe, with a sample of 5 stocks selected through purposive sampling and January Effect criteria. Data collection was carried out through documentation, and the analysis followed the steps of the Markowitz model, starting from gathering closing stock prices to determining the optimal portfolio. The findings reveal that four stocks are part of the optimal portfolio: BBTN 32.4%, BMRI 22.7%, ICBP 39.4%, and MEDC 5.5%. The portfolio’s expected return is 4.8 percent, with a portfolio risk of 3.6 percent, which is lower than the individual risk of any of the stocks in the sample