مطالب مرتبط با کلیدواژه

Copula


۱.

Studying the effects of USING GARCH-EVT-COPULA METHOD TO ESTIMATE VALUE AT RISK OF PORTFOLIO(مقاله علمی وزارت علوم)

نویسنده:
منبع: Iranian Journal of Finance, Volume ۲, Issue ۱, Winter ۲۰۱۸ 93 - 119

کلیدواژه‌ها: Value at Risk (VaR) Copula GARCH Extreme Value Theory (EVT) Backtesting

حوزه‌های تخصصی:
تعداد بازدید : ۴۸۰ تعداد دانلود : ۲۵۲
Value at Risk (VaR) plays a central role in risk management. There are several approaches for the estimation of VaR, such as historical simulation, the variance-covariance and the Monte Carlo approaches. This work presents portfolio VaR using an approach combining Copula functions, Extreme Value Theory (EVT) and GARCH-GJR models. We investigate the interactions between Tehran Stock Exchange Price Index (TEPIX) and Composite NASDAQ Index. We first use an asymmetric GARCH model and an EVT method to model the marginal distributions of each log returns series and then use Copula functions (Gaussian, Student’s t, Clayton, Gumbel and Frank) to link the marginal distributions together into a multivariate distribution. The portfolio VaR is then estimated. To check the goodness of fit of the approach, Backtesting methods are used. The empirical results show that, compared with traditional methods, the copula model captures the value more successfully.
۲.

Dynamic Cross Hedging Effectiveness between Gold and Stock Market Based on Downside Risk Measures: Evidence from Iran Emerging Capital Market(مقاله علمی وزارت علوم)

نویسنده:
منبع: Journal of Money and Economy, Vol. ۱۶, No. ۱, Winter ۲۰۲۱ 43-70

کلیدواژه‌ها: Cross Hedging Iran Emerging Capital Market Multivariate GARCH Copula Downside Risk

حوزه‌های تخصصی:
تعداد بازدید : ۲۷۰ تعداد دانلود : ۱۶۷
This paper examines the hedging effectiveness of gold futures for the stock market in minimizing variance and downside risks, including value at risk and expected shortfall using data from the Iran emerging capital market during four different sub-periods from December 2008 to August 2018. We employ dynamic conditional correlation models including VARMA-BGARCH (DCC, ADCC, BEKK, and ABEKK) and copula-GARCH with different copula functions to estimate volatilities and conditional correlations between Iran gold futures contract return and Tehran stock exchange main index return. The empirical results reveal that the dynamic conditional correlations switch between positive and near-zero values over the period under study. These correlations are high and positive during the major national currency devaluation and are low near to zero during other times. Out-of-sample one-step-ahead forecasts based on rolling window analysis show that DCC and ADCC multivariate GARCH models outperform other models for variance reduction, while a more interesting finding is that the copula-GARCH model outperforms other models for downside risks reduction.
۳.

Applying the GARCH and COPULA Models to Examine the Relationship Between Trading Volume and the Value of Trading with the Bubble Pricing(مقاله علمی وزارت علوم)

نویسنده:
منبع: Advances in Mathematical Finance and Application, Volume ۷, Issue ۲, Spring ۲۰۲۲ 423-435

کلیدواژه‌ها: volume of exchanges transaction value bubble price GARCH Copula

حوزه‌های تخصصی:
تعداد بازدید : ۱۹۴ تعداد دانلود : ۱۷۵
Given the importance of the securities market in each country's economy and the adverse effects of the price bubble on the irrational fluctuations of the stock market, it is clear that it must be prevented; therefore, with reference to the ambiguity of the factors causing the price bubble, research is underway. Investigating the relationship between the volume of transactions and the value of transactions with the price bubble in different industries of the Stock Exchange during the years 2006 to 2016 is a step towards recognizing this phenomenon.To investigate these communications, we used DCC-GJR-GARCH, diagonal BEKK and COPULA models. The results of the study of the relationship between the volume of exchanges and the value of exchanges with price bubbles suggest that there is a negative and complete correlation between them. In relation to the study of the relationship between price bubbles and research variables, we found that oil prices have a reverse and significant relationship with bubble prices. Other variables are not meaningful relationships with price bubbles. Also, in the study between variables of research with volume of transactions, it was determined that changes in tax volume and oil price variables have a reverse and significant relationship with the volume of transactions and the value of transactions with the volume of transactions has a direct and significant relationship.
۴.

Portfolio Optimization under Varying Market Risk Conditions: Copula Dependence and Marginal Value Approaches(مقاله علمی وزارت علوم)

نویسنده:
منبع: Advances in Mathematical Finance and Application, Volume ۹, Issue ۱, Winter ۲۰۲۴ 321 - 335

کلیدواژه‌ها: Asset Portfolio Extreme Value Theory Copula Market risk

حوزه‌های تخصصی:
تعداد بازدید : ۲۴۴ تعداد دانلود : ۲۰۹
This paper aims to investigate the portfolio optimization under various market risk conditions using copula dependence and extreme value approaches. According to the modern portfolio theory, diversifying investments in assets that are less correlated with one another allows investors to assume less risk. In many models, asset returns are assumed to follow a normal distribution. Consequently, the linear correlation coefficient explains the dependence between financial assets, and the Markowitz mean-variance optimization model is used to calculate efficient asset portfolios. In this regard, monthly data-driven information on the top 30 companies from 2011 to 2021 was the subject to consideration. In addition, extreme value theory was utilized to model the asset return distribution. Using Gumbel’s copula model, the dependence structure of returns has been analyzed. Distribution tails were modeled utilizing extreme value theory. If the weights of the investment portfolio are allocated according to Gumbel’s copula model, a risk of 2.8% should be considered to obtain a return of 3.2%, according to the obtained results.