We have introduced an early warning system for volatility regimes
regarding Tehran Stock Exchange using Markov Switching GARCH
approach. We have examined whether Tehran Stock Market has calmed
down or more specifically, whether the surge in volatility during 2007-
2010 global financial crises still affects stock return volatility in Iran.
Doing so, we have used a regime switching GARCH model. The data
consist of 3067 daily observations of the closing value of the Tehran
stock market from 29/09/1997 to 09/09/2010. The results indicate that
during the crisis period, Tehran stock exchange was in the high-volatility
regime. Smoothed probability plots show that the volatility in 2007-2009
was in high volatility regime but at 2009-2010, Volatility turned to low
volatility regime. Also, we have introduced an early warning system for
forecasting high volatility in Tehran Stock Exchange.