摘要：This study seeks to investigate the existence or absence of independence in return series in S&P index of the New York and 11 different indexes in Tehran Stock Exchange and their adherence to the random walk model in two Low volatility and high volatility regimes using the Markov switching model. Research sample included daily price information of 9 different industry indices of the bank, cement, oil products, machinery, chemicals, automobiles, sugar, food but sugar, metal minerals, index of 50 Top Companies and price index (TEPIX) in Tehran Stock Exchange Market for the period from 03/25/2011 to 03/19/2019. The results of the Markov Switching and Arima model showed that only in the high volatility regimes of the S&P index of the New York Stock Exchanges, with a durability of 32 percent, and the index of oil products in Tehran Stock Exchange with a 6 percent survival, the Arima model was not significant and in the rest The cases of the Arima model became significant.
