scholarly journals The influence of volatility spill-overs and market beta on portfolio construction

2015 ◽  
Vol 18 (2) ◽  
pp. 277-290 ◽  
Author(s):  
André Heymans ◽  
Wayne Peter Brewer

This study adds to Modern Portfolio Theory (MPT) by providing an additional measure to market beta in constructing a more efficient investment portfolio. The additional measure analyses the volatility spill-over effects among stocks within the same portfolio. Using intraday stock returns from five top-40 listed stocks on the JSE between July 2008 and April 2010, volatility spill-over effects were estimated with a residual- based test (aggregate shock [AS] model) framework. It is shown that when a particular stock attracted fewer volatility spill-over effects from the other stocks in the portfolio, the overall portfolio volatility decreased as well. In most cases market beta showcased similar results. Therefore, in order to construct a more efficient risk- adjusted portfolio, one requires both a portfolio that has a unit correlation with the market (beta-based), and stocks that showcase the least amount of volatility spill-over effects amongst one another. These results might assist portfolio managers to construct lower mean variance portfolios.


2020 ◽  
Vol 9 (4) ◽  
pp. 390-401
Author(s):  
AHSEN SAGHIR ◽  
SYED MUHAMMAD ALI TIRMIZI

The current study aims at the estimation of a group of variance-covariance methods using the data set of the non-financial sector of the Pakistan stock exchange. The study compares nine covariance estimators using two assessment criteria of root mean square error and standard deviation of minimum variance portfolios to gauge on accuracy and effectiveness of estimators. The findings of the study based on RMSE and risk behaviour of MVPs suggest that portfolio managers receive no additional benefit for using more sophisticated measures against equally weighted variance-covariance estimators in the construction of portfolios. Keywords: Variance-Covariance Estimators, Portfolio Construction, Mean-Variance Optimization.



2017 ◽  
Vol 6 (11) ◽  
pp. 270-278
Author(s):  
Pritpal Singh Bhullar ◽  
Pradeep K Gupta

Markowitz Portfolio theory is based on the expected return and risk but investors are more interested in realized return. The considerations, expected return as realized return and variance as investment risk, of Markowitz’s mean – variance model enable the researchers or scholars to further explore on the validity of Markowitz theory. The present study makes an attempt to unfold a new idea in investment scenario where Markowitz theory is empirically tested on realized return and risk as well as on realized return and expected return in the context of India. The findings show that a large variation in Expected Return is explained by the risk (Market Beta) alone and this risk and Expected return are significantly negatively related. However, the risk (Market Beta) and Realized return are insignificantly related. Further, a very low variation in the Realized (Actual) Return is explained by the Expected Return and the Expected Return and the Realised Return are insignificantly positively related. Thus, it is considered that the Markowitz model is not possible to implement in the real world even though the relationship holds good. This study acts as one of the guiding tools for investors in transforming their new age investment philosophy.



2016 ◽  
Vol 11 (02) ◽  
pp. 1650008
Author(s):  
SWARN CHATTERJEE ◽  
AMY HUBBLE

This study examines the presence of the day-of-the-week effect on daily returns of biotechnology stocks over a 16-year period from January 2002 to December 2015. Using daily returns from the NASDAQ Biotechnology Index (NBI), we find that the stock returns were the lowest on Mondays, and compared to the Mondays the stock returns were significantly higher on Wednesdays, Thursdays, and Fridays. The day-of-the-week effect on returns of biotechnology stocks remained significant even after controlling for the Fama–French and Carhart factors. Moreover, the results from using the asymmetric generalized autoregressive conditional heteroskedastic (GARCH) processes reveal that momentum and small-firm effect were positively associated with the market risk-adjusted returns of the biotechnology stocks during this period. The findings of our study suggest that active portfolio managers need to consider the day of the week, momentum, and small-firm effect when making trading decisions for biotechnology stocks. Implications for portfolio managers, small investors, scholars, and policymakers are included.



Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 394
Author(s):  
Adeel Nasir ◽  
Kanwal Iqbal Khan ◽  
Mário Nuno Mata ◽  
Pedro Neves Mata ◽  
Jéssica Nunes Martins

This study aims to apply value at risk (VaR) and expected shortfall (ES) as time-varying systematic and idiosyncratic risk factors to address the downside risk anomaly of various asset pricing models currently existing in the Pakistan stock exchange. The study analyses the significance of high minus low VaR and ES portfolios as a systematic risk factor in one factor, three-factor, and five-factor asset pricing model. Furthermore, the study introduced the six-factor model, deploying VaR and ES as the idiosyncratic risk factor. The theoretical and empirical alteration of traditional asset pricing models is the study’s contributions. This study reported a strong positive relationship of traditional market beta, value at risk, and expected shortfall. Market beta pertains its superiority in estimating the time-varying stock returns. Furthermore, value at risk and expected shortfall strengthen the effects of traditional beta impact on stock returns, signifying the proposed six-factor asset pricing model. Investment and profitability factors are redundant in conventional asset pricing models.



2021 ◽  
Vol 39 (11) ◽  
Author(s):  
Hussein Hasan ◽  
Hudaa Nadhim Khalbas ◽  
Farqad Mohammed Bakr AL Saadi

The aim of this research is to study the market reaction to the change of the managing director and how this change affects the abnormal returns of the shares. The research is based on the information published by the companies listed on the Iraq Stock Exchange, and 35 companies were selected for the period from 2015 to 2019. The results of the hypothesis test for this study show that there is a negative and significant relationship between the change of the managing director and abnormal stock returns. On the other hand, investors undervalue stock prices when changing CEOs. As a result, the stock returns are less than expected.



2021 ◽  
Vol 27 ◽  
pp. 92
Author(s):  
Shuzhen Yang

The objective of the continuous time mean-variance model is to minimize the variance (risk) of an investment portfolio with a given mean at the terminal time. However, the investor can stop the investment plan at any time before the terminal time. To solve this problem, we consider to minimize the variances of the investment portfolio in the multi-time state. The advantage of this multi-time state mean-variance model is the minimization of the risk of the investment portfolio within the investment period. To obtain the optimal strategy of the model, we introduce a sequence of Riccati equations, which are connected by jump boundary conditions. In addition, we establish the relationships between the means and variances in the multi-time state mean-variance model. Furthermore, we use an example to verify that the variances of the multi-time state can affect the average of Maximum-Drawdown of the investment portfolio.



Author(s):  
Nurfadhlina Bt Abdul Halima ◽  
Dwi Susanti ◽  
Alit Kartiwa ◽  
Endang Soeryana Hasbullah

It has been widely studied how investors will allocate their assets to an investment when the return of assets is normally distributed. In this context usually, the problem of portfolio optimization is analyzed using mean-variance. When asset returns are not normally distributed, the mean-variance analysis may not be appropriate for selecting the optimum portfolio. This paper will examine the consequences of abnormalities in the process of allocating investment portfolio assets. Here will be shown how to adjust the mean-variance standard as a basic framework for asset allocation in cases where asset returns are not normally distributed. We will also discuss the application of the optimum strategies for this problem. Based on the results of literature studies, it can be concluded that the expected utility approximation involves averages, variances, skewness, and kurtosis, and can be extended to even higher moments.



2021 ◽  
Vol 275 ◽  
pp. 01005
Author(s):  
Ruipeng Tan

This paper focuses on comparing portfolio management and construction before and after the coronavirus. First, this paper presents the importance of building up portfolios for investors to diversify their risks. Theories on portfolio management are discussed in this section to show how they have been developed to help on investing and reduce risk. Then, the paper moves on to show the impact of the pandemic on the financial market and portfolio management. Sample data on tech stock returns are collected to perform a Monte Carlo simulation on portfolio construction to find out the efficient portfolio before and after the COVID-19 outbreak. The efficient portfolio is build based on the Markowitz theory to find the combination. Comparisons between these portfolio constructions are made to find out the changes in portfolio management and construction under the pandemic era. In conclusion, this paper presents how pandemic has changed and impacted the investments and lists recommendations on future portfolio management and construction.



2019 ◽  
Vol 20 (1) ◽  
pp. 208-235 ◽  
Author(s):  
C Viljoen ◽  
B W Bruwer ◽  
Z Enslin

Risk disclosure practices have received increasing attention in the wake of the 2008 global financial crisis. This study investigated possible determinants relating to the composition of the board committee responsible for risk management, the frequency of board risk committee meetings and whether the company employs a chief risk officer, which could manifest in an enhanced level of risk-related disclosure. Based on the possible determinants identified in the literature, nine hypotheses were developed in order to investigate which of these determinants relate to an enhanced level of risk disclosure by the selected companies. The first required integrated reports of non-financial companies in the Top 40 index of the JSE Securities Exchange were investigated in this study. Regarding one area of investigation, namely the level of risk management disclosure, it was found that the disclosure of companies whose risk committee met more frequently and the disclosure of companies that employed a chief risk officer, were of a relatively higher standard. With regard to the other area of investigation, namely the level of risk identification and mitigation disclosure, no clearly significant determinant of enhanced disclosure was identified.



2019 ◽  
Vol 8 (1) ◽  
pp. 1-13
Author(s):  
Mohammad Farhan Qudratullah

Treynor Ratio merupakan model pioner inovatif ukuran kinerja saham yang dikemukakan Jack Treynor pada tahun 1965 yang terdiri atas 3 (tiga) komponen, yaitu return saham, return bebas risiko, dan beta saham. Banyak penelitian mendekati return bebas risiko dengan suku bunga termasuk saat mengukur kinerja saham syariah, sedangkan suku bunga dilarang dalam konsep keuangan islam. Tulisan ini membahas variabel alternatif untuk mendekati return bebas risiko selain dengan suku bunga (BI-Rate), yaitu dengan 4 (empat) pendekatan, yaitu: menghilangkan suku bunga, mengganti dengan zakat rate, mengganti dengan inflasi, dan mengganti dengan gross domestic produc (GDP) pada model Treynor Ratio yang diimplementasikan pada pasar modal syariah di Indonesia periode Januari 2011-Juli 2018. Hasil yang diperoleh adalah terdapat kesesuaian yang sangat tinggi hasil pengukuran model Treynor Ratio dengan suku bunga dengan keempat model lainnya. Namun, model-model tersebut tidak menjamin bahwa saham yang memilki kinerja terbaik pada saat ini akan memilki kinerja terbaik dimasa yang akan datang atau sebaliknya. Dilihat dari kedekatan hasil pengukuran kinerjanya, kelima model Treynor Ratio tersebut dapat dikelompokan jadi 2 (dua), yaitu model dengan suku bunga, model dengan inflasi, dan model dengan GDP sebagai kelompok pertama, sedangkan model tanpa suku bunga dan model dengan zakat-rate sebagai kelompok kedua. [Treynor Ratio is an innovative pioneer model the size of stock performance proposed by Jack Treynor in 1965 which consists of 3 (three) components, namely stock returns, risk free returns, and stock beta. Many studies approach risk-free returns with interest rates, including when measuring the performance of Islamic stocks, while interest rates are prohibited in the concept of Islamic finance. This paper discusses alternative variables to approach risk-free returns other than interest rates (BI-Rate), namely with 4 (four) approaches, namely: eliminating interest rates, changing zakat rates, changing inflation, and substituting gross domestic products (GDP) in the Treynor Ratio model that is implemented in the Islamic capital market in Indonesia for the period January 2011 - July 2018. The results obtained are very high conformity in the measurement results of the Treynor Ratio model with interest rates with the other four models. However, these models do not guarantee that stocks that have the best performance at this time will have the best performance in the future or vice versa. Judging from the closeness of the results of performance measurement, the five Treynor Ratio models can be grouped into 2 (two), namely models with interest rates, models with inflation, and models with GDP as the first group, while models without interest rates and models with zakat-rate as second group.]



Sign in / Sign up

Export Citation Format

Share Document