Measuring the Volatility Persistence of the Tehran Stock Exchange using Stochastic Volatility Models with Jump in Return

The long-term behavior of stock markets is of considerable importance to asset managers and financial experts due to its direct relationship with stock price valuation. Volatility persistence has a significant effect on stock price returns. Therefore, the relationship between heavy falls in the stock market can be related to the phenomenon of high volatility persistence. In the present study, using the Bayesian unit root test, the persistence of the Tehran stock Exchange volatility has been investigated in the framework of SV and SVJ. The results of this test using the Bayesian factor in different specifications of both SV and SVJ models show that although the unit root is rejected in the volatility of the Tehran stock Exchange prices in the period of 1398-1400 (2019-2021), the persistence of the volatility was very high. The increase of irrational traders in this period of time has been one of the reasons for increasing the persistence of market volatility. The findings show that the flow of information in the Tehran stock market and the absorption of information in its prices are slow. The characteristic of high volatility persistence in this market is the result of its closed structure and the concentration of market weight on a few main groups. As a result, regular release of financial statements, training of traders, and use of expert analysis along with diversification of investors and not focusing on specific pledges in portfolio formation will help to reduce volatility persistence.