In an efficient capital market, information rapidly affects the stock price of firms. The informational efficiency is classified as weak form, semi-strong form and strong form. The weak form efficiency indicates the random walk theory. If the market follows random walk, we cannot gain abnormal return.
The purpose of this study, using autocorrelation, run, unit root and variance ratio tests, is to concentrate on the market weak form efficiency of Tehran Stock Exchange subsections (TEFIX-30, TX-50 and the principle 44 companies offered in TSE). The results of this research are:
1. The 50 active companies index (TX-50) in TSE by using the four pre-told methods, is not weak form efficient.
2. 30 big companies index (TEFIX-30) by using the four pre-told methods, is not weak form efficient.
3. The principle 44 companies offered in TSE by using the four pre-told methods, is not weak form efficient.