An application of unit rate estimation on shareholders’ overreaction: Evidence from Tehran Stock Exchange

This paper characterizes the stockholders overreaction thorough return and price mean reverting behavior in specified ten major industry groups in Tehran Stock Exchange (TSE). For investigation of mean reversion presence, we use corporate firms from ten specified industry groups traded on the Tehran Stock Exchange and using a random walk with drift model with data over the period 2009-2013 period and recursive estimation in stability diagnostics test. The primary objective of this paper is to investigate mean reversion phenomenon in ten major industries including maximum number of real and nonstrategic investors with two different methods on quarterly return and monthly price time series. The results indicate that mean reversion occurred in the returns of these industry group. In addition, we use two major Unit Root Tests as complementary and final analysis. Out results also indicate that mean reversion takes place, significantly in eight industry groups and price time series in two industry groups follow a random walk process.