This paper explores the mechanism on how the persistence of the stock return volatility is created using a model of an agent-based stock market. First, artificial stock markets with different learning mechanisms, i.e., individual and social learning are examined. The simulation result shows that a social learning economy produces persistence of return volatility while an individual learning eco...

The purpose of this study is to compare the impacts of momentum on stock returns of companies listed in Tehran Stock Exchange in different market conditions. For this purpose, the sample size is 120 months from 2008 to 2017. The research hypotheses are estimated using multivariate linear regression using time series method. Based on the results of the hypotheses test, the momentum in each of th...

This paper examines the hypothesis that both stock returns and volatility are asymmetrical functions of past information derived from domestic and US stock-market news. By employing a double-threshold regression GARCH model to investigate four major index-return series, we find significant evidence to sustain the asymmetrical hypothesis of stock returns. Specifically, evidence strongly supports...

Recently, the economic crisis has resulted in instability in stock exchange market and this has caused high volatilities in stock value of exchanged firms. Under these conditions, considering uncertainty for a favorite investment is more serious than before. Multi-objective Portfolio selection (Return, Liquidity, Risk and Initial cost of Investment objectives) using MINMAX fuzzy goal programmin...

This paper investigates the relationship between aggregate stock market trading volume and the serial correlation of daily stock returns. For both stock indexes and individual large stocks, the first-order daily return autocorrelation tends to decline with volume. The paper explains this phenomenon using a model in which risk-averse "market makers" accommodate buying or selling pressure from "l...

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.  ...