SUMMARY
The presence of the stock market has helped to increase economic growth in a country. However, high levels of volatility plus economic uncertainty make investors have to rethink investing in the capital market. This study aims to examine the share of each industrial sector on the stock exchange in Indonesia by testing the Efficient Market Hypothesis (EMH) and forecasting the growth of returns for each industry. The method that will be used in this study includes variance ratio, data stationarity test, Autoregressive Integrated Moving Average (ARIMA), and Autoregressive Conditional Heteroskedasticity (ARCH). The results show that the industrial sectors on the Indonesia Stock Exchange are inefficient in the weak form. In forecasting, almost all indices experience a contraction of growth at the beginning of the forecasting period. The stakeholders are expected to be more active in the market by frequently buying and selling securities because the market is proven inefficient, and the market can be defeated.