Global financial crisis and dependence risk analysis of sector portfolios: a vine copula approach

We use regular vine (r-vine), canonical vine (c-vine) and drawable vine (d-vine) copulas to examine the dependence risk characteristics of three 20-stock portfolios from the retail, manufacturing and gold-mining equity sectors of the Australian market in periods before, during and after the 2008–2009 global financial crisis (GFC). Our results indicate that the retail portfolio is less risky than the manufacturing counterpart in the crisis period, while the gold-mining portfolio is less risky than both the retail and manufacturing sector portfolios. Both the retail and gold stocks display a higher propensity to yield positively skewed returns in the crisis periods, contrary to the manufacturing stocks. The r-vine is found to best capture the multivariate dependence structure of the stocks in the retail and gold-mining portfolios, while the d-vine does it for the manufacturing stock portfolio. These findings could be used to develop dependence risk- and investment risk-adjusted strategies for investment, rebalancing and hedging which more adequately account for the downside risk in various market conditions.     

Oil price and Gulf Corporation Council stock indices: New evidence from time-varying copula models

Using a time-varying GJR copula approach, we determine the conditional dependence of the GCC stock indices on oil price between 2007 and 2016. We show how to improve the forecasting accuracy of the co-movement of energy and stock prices in an equally weighted portfolio. Contrary to prior findings, we demonstrate that due to the different co-movements across the GCC stock indices, portfolios of oil assets and several GCC stocks are less likely to be affected by systemic risk. The different co-movements across several stock indices over time provide different entry and exit points for stock investors. This approach is in line with the ‘buy low/sell high’ adage.     

Regional and copula estimation effects on EU and US energy equity portfolios

ABSTRACT

The aim of this paper is to investigate the regional interdependence structure of energy equities in the US and in the EU. Based on weekly stock prices of 28 big energy firms in the two regions from 2008 to 2019, we compare the efficiency of using bivariate or multivariate copulas to describe the dependence structure of energy equities. Furthermore, we investigate the impact of the choice between these two methods on the performance of energy equity portfolios. Our empirical results show that multivariate copulas, such as C-Vine, allow to better describe the dependence structure of energy equities. We also find that there is a stronger and more complex dependence structure among EU energy equities than among US energy equities. Our scenario analysis also shows that the dependence structure is stronger during the GFC while being weaker during the ESDC. More importantly, the correlation matrix obtained from the multivariate copula method allows to obtain optimal mean-CVaR portfolios with a higher performance than that from the bivariate copula method. More importantly, optimal portfolios constituted with multivariate copulas allow to reduce the portfolio’s sensitivity to oil prices.     

中国股市价值反转投资策略有效性实证研究

本文以中国深沪A股股票市场为考察对象 ,分析了价值反转投资策略的有效性。作者通过实证分析发现 :在中国深沪A股股票市场上 ,以帐面价值与市场价值比 (B M)、B M GS等指标构造的价值反转投资策略可以产生显著的超额收益率 ,并且其显著程度因持有期不同而不同。接着 ,作者利用CAPM模型、Fama French三因素模型并引入了协偏度 (coskewness)和协峰度 (cokurtosis) ,构造出多风险因子模型来解释价值反转投资策略超额收益率。我们发现 :在经过传统风险因素调整后 ,价值反转投资策略效果依然明显 ;CAPM模型无法解释价值反转投资策略超额收益率 ;Fama French三因素模型对价值反转投资策略超额收益率的解释能力最为显著 ,但对于有些价值投资策略 ,在Fama French三因素基础上加上协偏度和协峰度因子后 ,模型的解释能力有所提高     

Investment horizon effect on asset allocation between value and growth strategies

How does the optimal risk exposure of assets change as their investment horizons increase? Does this impact investment portfolio decision-making, in particular, optimal asset allocation between value and growth strategies over various investment horizons? This paper adopts a new approach to address these questions by examining portfolio allocation between value and growth stocks over various investment horizons. This new approach is based on wavelet analysis, which decomposes the returns of a particular investment strategy across multiple investment horizons. The key empirical results show that the success of pursuing the value strategy (short-selling growth stocks and going long on value stocks) is impacted by the approach used to classify value and growth stock returns. We explore two common alternatives: Fama-French versus Standard & Poor's (S&P) 500/Barra portfolios. The results using Fama-French portfolios show that as the investment horizon increases, the optimal mean allocation of investors tilts heavily away from growth stocks, particularly for lower and moderate levels of risk aversion. Interestingly, for S&P 500/Barra portfolios the allocation weights between value and growth do not vary much.     

Performance of value- and size-based strategies in the Italian stock market

This paper investigates the performance of size- and value-based strategies in the Italian stock market in the period 2000–2018. Previous research argued the impossibility to define properly value-sorted portfolios due to the inaccuracy of book-to-market ratios available for Italian listed stocks. Using more accurate data, we implement portfolios sorting based on value and growth stocks, to assess the relevance of the value factor in the Italian stock market. We find that the capital asset pricing model fails to explain the cross-section of returns on the different strategies while the Fama and French three-factor model provides a better fit. The results show that all three factors are significant in explaining Italian stock returns during the sample period. Unlike previous studies, which either found no value effect at all or no clear-cut results when testing the book-to-market variable, we find that the value factor is statistically significant and the associated risk premium is of a considerable size.     

Dynamic causality between the U.S. stock market,the Chinese stock market and the global gold market: implications for individual investors’ diversification strategies

This paper proposes a generalization of the prior VAR and EGARCH model to explore the linkage between returns and volatility transmissions in the U.S. stock market, the Chinese stock market, and the global gold market from 10 July 1996 to 20 July 2018. We found that past returns of the U.S. stock market can predict the current returns of the other two markets, and that significant reciprocal volatility transmission existed within and across all three markets. We further implemented average out-of-sample (OOS) forecasting to show that a risk-adjusted portfolio, such as mean-variance with sample estimator, does not outperform an equal-weighted portfolio. This provides insights for individual investors and helps to explain the ongoing disagreement in the portfolio literature concerning the effectiveness of risk-adjusted portfolios and equal-weighted portfolios when the number of assets is small.     

Exchange rates change,asset-denominated currency difference and stock price fluctuation

This paper examines differences in the connectedness between exchange rates and stock prices for companies with different asset currencies on the Hong Kong stock market, and it seeks to explain those differences by proposing a hypothesis on asset-denominated currency difference. Under a framework of investor heterogeneity, we establish a dynamic, discrete theoretical model to analyse the connectedness between exchange rates, the stocks of local Hong Kong companies, the stocks of companies from the mainland and foreign exchange interventions. Using monthly data from January 2000 to August 2018, we adopt the time-varying parameter vector auto-regression (TVP-VAR) model to empirically study the dynamic relationships between exchange rates and the prices of both Hong Kong-based and mainland-based stocks. The results show significant differences in the ways that exchange rates and prices for the two types of stocks are linked. The exchange rates are positively correlated with mainland stocks and negatively correlated with Hong Kong stocks. Moreover, foreign exchange intervention is found to be an effective means for stabilising exchange rates, although such intervention tends to increase stock volatility.

Abbreviations: TVP-VAR - time-varying parameter vector auto-regression model; MCMC - Monte Carlo-Markov Chain method.     

Assessing volatility transmission between Brent and stocks in the major global oil producers and consumers – the multiscale robust quantile regression

This paper investigates the volatility transmission effect between Brent oil futures and stock markets in the major global oil producing and consuming countries – the U.S., Russia, China and Saudi Arabia. In that process, we employ a mixture of novel and elaborate methodologies – wavelet signal decomposing procedure, GARCH model with complex distribution and recently developed robust quantile regression. Our results indicate that the effect is stronger in short-term horizon than in midterm and long-term in most cases. The magnitude is much stronger in turbulent times, whereas in tranquil times, this effect is very weak. We find that Russian RTS index endures the strongest volatility transmission effect from oil market. Surprisingly, Saudi stock market does not suffer heavy spillover effect even in the periods of increased market unrest. In the U.S. and China, the effect is much stronger from stocks to oil than vice-versa, and this particularly applies for the U.S. case.

     

Can investors of Chinese energy stocks benefit from diversification into commodity futures?

We attempt to evaluate the diversification potential of commodity futures for energy stocks in China. With a variety of copula functions and three risk-based dynamic measures, our results show that even though commodity futures are not helpful in improving the risk-adjusted returns of energy stocks, they can significantly reduce the volatilities and expected-shortfalls of the diversified portfolios. Such diversification benefits are much larger during large market downturns than during normal times. In particular, gold (copper) futures are the most (least) attractive in diversifying risks of energy stocks in most cases. The results also highlight that the non-linear dependence cannot be ignored when estimating the diversification benefits, and more various risk hedging strategies are expected for investors holding energy stocks, especially coal company stocks.     

Is gold a weak or strong hedge and safe haven against stocks? Robust evidences from three major gold-consuming countries

In this article, we test nexus between gold and stocks for the three major gold consumers by using the range of methodologies. First, we assess if there is any time-varying correlation between the two assets. We fail to find any significant time-varying correlation between gold and stock returns in India and the United States. Second, we attempted to investigate the safe-haven property of gold by analysing the decile-wise conditional correlation between stock returns and gold returns at different deciles of stock returns. Third, in order to test the robustness of the results drawn from the decile-wise correlation, we employ wavelet coherence in continuous wavelet framework to test the time and frequency varying nexus between the pair of assets. The range of methodologies employed seems to indicate the weak hedge and safe haven-property of gold for stocks.     

Security analyst firm reputation and investors’ response to forecasted stocks in the biotechnology sector

ABSTRACT

Stock analyst reputation bridges the gap between technical knowledge of the high-technology and the investor's response to its stock, implying that the reputation of the stand-alone analyst serves this purpose. However, global firms have a stronger influence on their stock analysts than do small firms with 2 personnel. Does firm reputation affect the individual analyst and attract investor attention to forecasted stocks? Evidence from SAFs (security analyst firms) in the biotechnology sector supports this question and proposition. Four moderators (interactive predictors of organisational reputation) show positive correlations. They are the SAF's age, size, performance, and media coverage. These organisational level measures contribute to the institutional theory compared to the literature that focuses on the individual analyst without their organisations. In line with institutional theory, we make three explicit points. First, high uncertainty in the biotechnology sector turns investors to the organisational legitimacy and reputation of the analyst. Second, the organisational age, size, performance and media coverage of the security firm reduces uncertainty of the investor in the biotechnology sector. Third, the reputation of security firm flow to its individual analysts as well as from the individual analyst to the security firm. Thus, the organisational context matters in a social setting.     

When Do Opening Stock Returns Tend to be Higher?

Abstract

In this study, I make an effort to formulate a trading rule that would make use of some systematic interday patterns in individual stocks’ opening returns. I analyze intraday price data on all the stocks that were S&P 500 Index constituents during the period from 1993 to 2012. I document that if the general market direction of the previous day's opening session is controlled for, then a stock's opening return tends to be higher if, on the previous trading day, its opening return was relatively high (either positive, or higher than the same day's opening market return) and its open-to-close return was relatively low (either non-positive, or lower than or equal to the same day's open-to-close market return). Finally, for the sampling period, I construct two different investment portfolios involving a long position in the stocks on the days when, according to the findings, their opening returns are expected to be high and a short position in the stocks on the days when, according to the findings, their opening returns are expected to be low. Both portfolios are found to yield significantly positive returns, providing evidence for the practical applicability of the documented patterns in opening stock prices.     

Oil shocks and stock volatility: new evidence via a Bayesian,graph-based VAR approach

ABSTRACT

This article examines the temporal dependence between three oil shocks and realized volatility in the stock markets of G20 countries between 1994 and 2019. By applying a novel, graphical, Bayesian VAR (BGVAR) model, we calculate unidirectional linkages of oil and stock volatility with a full and segmented sample. The results suggest an overall causality from stock volatility to oil shocks. For certain short, specific periods, the causal direction reverses. Depending on the country and the source of an oil shock, the magnitude and type of the effect can vary considerably. Specific oil-market shocks occur most often in our full sample. In a time-varying structure, oil supply shocks’ impact on stock volatility is more prominent, and net oil-importing countries’ responses to these shocks are greater than for oil-exporting countries. In addition, we find that relationship dynamics can capture market information, such as global economic growth during the 2008–2009 financial crisis.     

Market Underreaction and Overreaction of Technology Stocks

Several studies have assessed stock market under- or overreaction of stocks and there is some agreement among them. However, there is much disagreement about what constitutes market underreaction or overreaction, and the conditions that cause it. The substantial variation in results among studies may be partially attributed to the types of firms that are contained in any sample. We investigate this premise by focusing on a sample of technology stocks that experienced an extreme change in stock price, along with a corresponding control sample of non-technology stocks that experienced a similar extreme change in stock price on the same day.

Based on the subsequent stock price behavior of each sample, we find a greater degree of overreaction within extreme positive changes in technology stock prices (winners) than in non-technology stock prices. In addition, we find a greater degree of underreaction within extreme negative changes in technology stock prices (losers) than in non-technology stock prices. When considering winners and losers collectively for technology and non-technology firms, it appears the market is overoptimistic when it initially revalues technology stock prices relative to non-technology stock prices.

The degree of under- or overreaction of technology stocks varies within the sample of technology stocks, and is conditioned on firm-specific characteristics. Overall, our results suggest that technology stocks exhibit unique stock price behavior subsequent to an extreme change in price, and that this unique behavior can even vary among technology firms according to firm-specific characteristics.     

Dividend-Driven Trading Strategies: Evidence from the Warsaw Stock Exchange

This study presents an analysis of dividend-driven trading strategies based on dividend yield growth effects in the Polish stock market in the years 1994–2004. Results indicate that the dividend yield growth portfolios were capable of beating the market in the entire sample period. Their performance, however, was not consistent over time and the highest returns were obtained during final years. Empirical findings based on the analysis of different types of portfolios demonstrate the importance of dividends as a source of significant fundamental information items from stock market companies. At the same time, they show that a dividend investment strategy for the Polish stock market is most successful when the selection of stocks for the dividend yield growth portfolios is subject to further restrictions, most notably concerning company size.

Do short sellers outperformthe market?

During the current financial crisis, short sellers have been blamed for causing or at least accelerating the crash of the financial market. They have been accused of manipulating stock prices so that they would fall and getting rich at the ‘naive’ investors' expense. This study investigates the validity of these accusations by following the TA100 Index and four designed portfolios during the period 2006 to 2008. The designed portfolios were constructed in accordance with the weekly report on short selling activity issued by the Tel Aviv Stock Exchange. The results show that short sellers did not succeed in outperforming the market during that 3-year period. Moreover, the portfolios that did not include the stocks picked by the short sellers performed more poorly (they should have been sold short) than the portfolios that included stocks chosen by the short sellers. These results contradict the hypothesis that short selling disrupts market efficiency.     

Do speculative bubbles migrate in the Chinese stock market?

In this paper, a duration dependence test for speculative bubbles in the Chinese stock market is developed. It is found that bubbles in the aggregate stock price existed before the split share reform. After the reform, we observe the phenomenon of bubble migration across industries. In particular, bubbles migrate from the telecommunications industry to the health care industry. Moreover, we find that monetary policy used to have a significant impact on the bubble size before the reform but the impact diminished after the reform.

     

The momentum effect on Chinese real estate stocks: Evidence from firm performance levels

This paper investigates the momentum effects under different firm performance levels for Chinese real estate stocks using quantile regression with a dummy variable estimator. This paper finds that regardless of the momentum horizon, the momentum effects are positive under high-performing individual stocks, but they are negative under low-performing individual stocks. While prior literature only finds that this asymmetric phenomenon appears under different market states, and the findings on different horizons are inconsistent. Furthermore, this paper finds that the positive (negative) momentum effect under high (low) firm performance levels is stronger than that under bullish (bearish) markets. This implies that superior (inferior) fundamental business performance and bullish (bearish) markets can cause the stock prices to go up (down); however, the effect of the former is stronger than that of the latter. Moreover, this paper finds that the relation between future returns and past turnover ratios is positively correlated under high-performing stocks, but negatively correlated under low-performing stocks. Based on the above findings, this paper regards past turnover ratios as a leading indicator of stock returns and suggests two profitable investment portfolios which are superior to the average returns of real estate stocks.     

Home Bias in International Stock Return Expectations

Despite the advantages of international portfolio diversification, actual equity portfolio holdings reveal a strong bias towards domestic stocks. One hypothesis is that this bias can be explained by stock return expectations expressed in probability judgments. To test that hypothesis and to analyze the underlying effects that might cause distortions in investors' expectations, we conducted a cross country study in Germany and the U.S. comparing participants' judgments about an identical set of German and U.S. stocks.

Results show that both test groups feel more competent about domestic stocks. The asymmetric perception of competence is connected with an asymmetric assessment of probabilities. For both test groups subjective probability distributions of stock returns are significantly less dispersed and more optimistic for stocks associated with high competence levels than for stocks associated with low competence levels.