Percorrer por autor "Hammoudeh, Shawkat"
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- Downside risk and portfolio diversification in the euro-zone equity markets with special consideration of the crisis periodPublication . Liu, Tengdong; Hammoudeh, Shawkat; Santos, Paulo AraújoThis study examines the Value-at-Risk for ten euro-zone equity markets individually and also divided into two groups: PIIGS (Portugal, Italy, Ireland, Greece and Spain) and the Core (Austria, Finland, France, Germany and the Netherlands), employing four VaR estimation and evaluation methods considered over the full period and the pre- and post-global crisis subperiods 1 and 2. The backtesting results are also evaluated according to the Basel capital requirements. The results demonstrate that the CEVT methods meet all the statistical criteria the best for most individual equity indices over the full period, but these results over the two subperiods for those two methods are mixed, compared to those the DPOT methods. Moreover, the two optimal group portfolios of the PIIGS and the Core as well as the grand portfolio that combines the ten indices do not show much diversification benefits. The PIIGS portfolio selects Spain's IBEX only, while that of the Core opts for Austria's ATX only in the full period and subperiod 1. However, Germany's DAX overwhelmingly dominates both the Core and the Grand portfolios in subperiod 2.
- Downside risk management and VaR-based optimal portfolios for precious metals, oil and stocksPublication . Hammoudeh, Shawkat; Araújo Santos, Paulo; Al-Hassan, AbdullahValue-at-Risk (VaR) is used to analyze the market downside risk associated with investments in six key individual assets including four precious metals, oil and the S&P 500 index, and three diversified portfolios. Using combinations of these assets, three optimal portfolios and their efficient frontiers within a VaR framework are constructed and the returns and downside risks for these portfolios are also analyzed. One-day-ahead VaR forecasts are computed with nine risk models including calibrated RiskMetrics, asymmetric GARCH type models, the filtered Historical Simulation approach, methodologies from statistics of extremes and a risk management strategy involving combinations of models. These risk models are evaluated and compared based on the unconditional coverage, independence and conditional coverage criteria. The economic importance of the results is also highlighted by assessing the daily capital charges under the Basel Accord rule. The best approaches for estimating the VaR for the individual assets under study and for the three VaR-based optimal portfolios and efficient frontiers are discussed. The VaR-based performance measure ranks the most diversified optimal portfolio (Portfolio #2) as the most efficient and the pure precious metals.
- Downside risk, portfolio diversification and the financial crisis in the euro-zonePublication . Sarafrazi, Soodabeh; Hammoudeh, Shawkat; Santos, Paulo AraújoThis paper evaluates the value at risk for individual sovereign bond and national equity markets for 10 member countries in the euro-zone, using four estimation models and three accuracy criteria in addition to the daily capital requirements, for the full sample period and a subperiod that marks the beginning of the recent global financial crisis. The results show that the conditional extreme value theory model under both the normal and Student-t distributions satisfies the four accuracy criteria the best and gives the least capital charges for both periods, while the RiskMetrics gives the worst results. These euro-zone bond and equity markets are also classified into two groups: the PIIGS (Portugal, Italy, Ireland, Greece and Spain) and the Core (Germany, France, Austria, The Netherlands and Finland), and optimal portfolios are constructed for these two groups as well as for the ten euro area as a whole. Given the sample periods, the results show no strong diversification for any of the two groups or for the whole area in any of the bond and equity asset classes or both. The bond and equity portfolios are augmented with commodities and the best grand portfolio is the one that is diversified with the commodities gold, silver and oil, particularly for the subperiod.
- High quantiles estimation with Quasi-PORT and DPOT:an application to value-at-risk for financial variablesPublication . Santos, Paulo Araújo; Alves, Isabel Fraga; Hammoudeh, ShawkatRecurrent “black swans” financial events are a major concern for both investors and regulators because of the extreme price changes they cause, despite their very low probability of occurrence. In this paper, we use unconditional and conditional methods, such as the recently proposed high quantile (HQ) extreme value theory (EVT) models of DPOT (Duration-based Peak Over Threshold) and quasi-PORT (peaks over random threshold), to estimate the Value-at-Risk with very small probability values for an adequately long and major financial time series to obtain a reasonable number of violations for backtesting. We also compare these models and other alternative strategies through an out-of-sample accuracy investigation to determine their relative performance within the HQ context. Policy implications relevant to estimation of risk for extreme events are also provided.