This study aims to determine the optimal
portfolio formation by using the Markowitz model on the
IDX30 index stock, in order to obtain stocks that are used
as investment choices or form a portfolio. The population
in this study is all shares of issuers or companies that have
been included in the IDX30 Index on the Indonesia Stock
Exchange for the period February 2017-January 2022, as
many as 53 companies while the sample in this study was
50 company shares selected based on nonprobability
sampling technique with purposive sampling method.
Data collection is done by using documentation
techniques. Data analysis was performed using the
Markowitz model. The results of this study indicate that
of the 50 IDX30 Index stocks that were used as research
samples, 14 stocks were included in the optimal portfolio,
namely ICBP, MIKA, TLKM, ACES, UNTR, CPIN,
MDKA, BBCA, TOWR, ADRO, KLBF, PTBA, TBIG,
ANTM stocks. The optimal portfolio that is formed
produces an expected return portfolio value of 0.0075 or
0.75% per month with a portfolio risk level of 0.0313 or
3.13% per month. The formation of an optimal portfolio
is more recommended for investors who want to invest in
IDX30 Index shares on the Indonesia Stock Exchange.
This is because the portfolio formed as a form of
investment diversification is provento be able to reduce
investment risk compared to investing in only one stock.
Keywords : Using the Markowitz Model in the Analysis of Optimal Portfolio Forming on Idx30 Index Stock on the Indonesia Stock Exchange.