Market Portfolio Research Articles

Evidence of Uniform Inefficiency in Market Portfolios Based on Dominance Tests

We find stochastic uniform inefficiency of many widely held (active) portfolios and fund strategies relative to popular benchmarks. Uniformity provides robust findings over general classes of utility (loss) functions and unknown distribution of returns. Evidence is based on statistical tests for the null of stochastic uniform inefficiency of a given portfolio. The alternative is that there is at least one portfolio that dominates it. We derive an analytical characterization of stochastic uniform inefficiency. We give the limit distribution for the empirical test statistic, and present a practical implementation with block bootstrap for consistent estimation of p-values. Our test is asymptotically exact and performs well in Monte Carlo experiments.

The Macroeconomic Announcement Premium

Empirical studies demonstrate striking patterns in stock market returns in relation to scheduled macroeconomic announcements. First, a large proportion of the total equity premium is realized on days with macroeconomic announcements, despite the small number of such days. Second, the relation between market betas and expected returns is far stronger on announcement days as compared with non-announcement days. Finally, these results hold for fixed-income investments as well as for stocks. We present a model with rare events that jointly explains these phenomena. In our model, which is solved in closed form, agents learn about a latent disaster probability from scheduled announcements. We quantitatively account for the empirical findings, along with other facts about the market portfolio.

A remark on mean‐semivariance behaviour: Downside risk and capital asset pricing

AbstractIn the conventional capital asset pricing model (CAPM), standard deviation as a measure of risk penalizes both upward and downward movements. However, while downward movements in investments are risky, upward movements are favourable. Therefore, standard semideviation that treats only those negative differences in returns over the benchmark as risky was proposed as a measure of downside risk. Attempts have been made to obtain the formulation of beta in this context, called downside beta. In this work, CAPM in the mean‐semivariance framework (D‐CAPM), with semivariance measured in terms of negative deviation around expected return, is derived and established that the model proposed earlier with a version of downside beta with respect to this definition of semivaraince is invalid. The appropriate version of downside beta is obtained, and under the rectified formulation, the validity of the true D‐CAPM is empirically tested during July 2013–July 2018. The solution to the tangent point is also obtained. The proportion of investment in the stocks in the tangent portfolio and the downside beta for the stocks in the tangent portfolio are determined. We find that there is no evidence to disprove that D‐CAPM holds true considering either Nifty 50 or S&P BSE Sensex as market portfolio.

Product Market Competition and the Stock Market: Capitalisation, Returns and Betas.

We develop a tractable RBC model of the stock market with heterogenous firms. Shares value rests on the rent extracted from proprietary technology a la Dixit-Stiglitz. We prove the existence and uniqueness of the fundamental equilibrium. Closed form solutions are provided for the market portfolio and for individual firms' valuations, and for each stock's beta, under weak assumptions on the shock processes. An increase in the degree of monopoly unambiguously increases the stock market capitalisation and reduces the stock index return. As the Lerner index tends to one, the idiosyncratic components of individual returns, generated by the productivity shocks, tend to vanish: the stock market can no longer provide instruments for trading risk beyond the stock index.

Do limits to arbitrage explain the benefits of volatility-managed portfolios?

We investigate whether transaction costs, arbitrage risk, and short-sale impediments explain the abnormal returns of volatility-managed equity portfolios. Even using six cost-mitigation strategies, after transaction costs, volatility management of asset-pricing factors besides the market return generally produces zero abnormal returns and significantly reduces Sharpe ratios. In contrast, abnormal returns of the volatility-managed market portfolio are robust to transaction costs and concentrated in the most easily arbitraged stocks, those with low arbitrage risk and impediments to short selling. Moreover, the managed market strategy only provides superior performance when sentiment is high, consistent with prior theory that sentiment traders underreact to volatility.

Ergodicity Economics and the High Beta Conundrum

Using Ergodicity Economics this paper shows that terminal wealth maximizing portfolios have betas that are substantially higher than the market portfolio (beta = 1). Simulations indicate that uncertainty about the future distribution of returns and the high cost of over-betting could be limiting factors to implementing such high beta portfolios. Another possibility is that investors do care about risk and are trying to maximize some form of risk adjusted growth rate.

Cross-Country Stock Market Integration and Portfolio Diversification Opportunities Evidence from Developed, Emerging and Frontier Countries

This study examines the stock market integration in cross-regional countries of developed, emerging, and frontier markets based on low correlation. The objective of the study is to identify the diversification opportunities and link between correlation and integration among country-level stocks. For this purpose, we select 62 countries from all three classifications of developed, emerging, and Frontier Markets. We constructed portfolios by selecting least 5 correlated countries denoted with Pjt in which each country has a correlation of less than .10 with base country Pit. Thirty-two countries fulfill the criteria of low correlation; 7, 13 and 12 from developed, emerging and frontier markets, respectively. Panel co-integration and VECM are applied to test the stock market integration and long & short-run linkages between country-level portfolios designed based on low correlation criteria. After conditioning for oil price movements, S&P 500 and exchange rate, we found Canada, France and Germany from developed category; Chile, Colombia, Greece, South Korea, Malaysia, Pakistan and Philippine from emerging category; and Bahrain, Jordan, Kuwait, Morocco, and Sri Lanka from frontier category have long-run diversification opportunities. Countries including; Canada and Italy from developed category; Argentina, Chile, China, Colombia, India, Indonesia, South Korea, Mexico and the Philippine from emerging category; and Bahrain, Kuwait, Morocco, Nigeria, and Tunisia from emerging category have short-run diversification opportunities.

Emerging market portfolios and Islamic financial markets: Diversification benefits and safe havens

We examine the relationship between Islamic and conventional stock market returns to see if Islamic financial markets provide portfolio diversification benefits and safe havens during turbulent times. Using daily data from January 1996 through September 2020 we consider conventional emerging stock market returns and some Islamic stock market returns and examine their interactions using causality-in-variance, dynamic conditional correlations, optimal hedge ratios, and causality-in-risk tests. Causality-in-variance test results show causality between Islamic stock returns and all emerging stock returns which indicates Islamic markets provide limited safe havens. Results from both time-varying conditional correlations and the hedge ratios show that there are positive and significant correlations between emerging stock markets and Dow Jones Islamic Market Index, which implies limited portfolio diversification benefits afforded by Islamic stock markets.

Evidence of Uniform Inefficiency in Market Portfolios Based on Dominance Tests

We find stochastic uniform inefficiency of many widely held (active) portfolios and fund strategies relative to popular benchmarks. Uniformity provides robust findings over general classes of utility (loss) functions and unknown distribution of returns. Evidence is based on statistical tests for the null of stochastic uniform inefficiency of a given portfolio. The alternative is that there is at least one portfolio that dominates it. We derive an analytical characterization of stochastic uniform inefficiency. We give the limit distribution for the empirical test statistic, and present a practical implementation with block bootstrap for consistent estimation of p-values. Our test is asymptotically exact and performs well in Monte Carlo experiments.

Estimación del Riesgo de Mercado utilizando el VaR y la Beta del CAPM

El objetivo de este estudio es medir el riesgo de mercado de portafolios de acciones del mercado financiero mexicano en periodos de alta volatilidad mediante cuatro metodologías: 1) la Beta del CAPM (-CAPM), 2) el VaR-Simulación Histórica (VaR-SH), 3) VaR-Delta Normal (VaR-δN) y 4) VaR-Simulación Montecarlo (VaR-SM). Estas métricas se seleccionaron por ser parsimoniosas. Los resultados muestran que las metodologías son consistentes en periodos de alta volatilidad. Se recomienda calcular la composición del portafolio de mercado y su VaR, para hacerlas comparables. La limitante principal, es que la -CAPM únicamente se puede calcular para portafolios de acciones, mientras que el cálculo del VaR con estas metodologías no contempla la ocurrencia de eventos extremos. Esto implica que los niveles de riesgo podrían subestimarse en periodos de alta volatilidad. La originalidad de este estudio reside en la comparación de estas metodologías mediante el cálculo de la composición del portafolio de mercado. Concluimos que el VaR-SH estima un mayor riesgo que la -CAPM después de experimentarse la alta volatilidad, si bien la -CAPM es consistente para las metodologías de VaR empleadas.

The Active vs Passive: Smart Factors, Market Portfolio or Both?

While there may be debates about passive and active investing, and even blogs about the numbers of active funds that were outperformed by the market, the history taught us that the outperformance of active or passive investing is cyclical. As a proxy for the active investing, the paper examines factor strategies and their smart allocation using fast or slow time-series momentum signals, the relative weights based on the strength of the signals and even blending the signals. While the performance can be significantly improved, using those smart approaches, the factors still got beaten by the market in both US and EAFE sample. However, the passive approach did not show to be superior. The factor strategies and market are significantly negatively correlated and impressively complement each other. The combined Smart Factors and market portfolio vastly outperforms both factors and market throughout the sample in both markets. With the combined approach, the ever-present market falls can be at least mitigated or profitable thanks to the factors.

Flow-Driven ESG Returns

I show that the performance of ESG investments is strongly driven by price-pressure arising from flows towards sustainable funds, causing high realized returns that do not reflect high expected returns. The coefficient linking ESG flows and realized returns is the product of two factors: The deviation of green funds' portfolios from the market portfolio and a flow multiplier matrix that is the inverse of the market's demand elasticity of substitution between stocks. Empirically, withdrawing 1 dollar from the market portfolio and investing it in the representative ESG fund increases the aggregate value of high ESG-taste stocks by 2-2.5 dollars. Under the absence of flow-driven price pressure, the aggregate ESG industry would have strongly underperformed the market from 2016 to 2021. Furthermore, the positive alpha of a long-short ESG taste portfolio becomes significantly negative.

A Note on the CAPM With Endogenously Consistent Market Returns

I demonstrate that with the market return determined by the equilibrium returns of the CAPM, expected returns of an asset are affected by the risks of all assets jointly. Another implication is that the range of feasible market returns will be limited and dependent on the distribution of weights in the market portfolio. A large and well diversified market with no dominating asset will only return zero while a market dominated by a small number of assets will only return the risk-free rate. In the limiting case of atomistic assets, we recover the properties of the standard CAPM.

Pursuing Multiple Premiums: Combination vs. Integration

This paper compares two different approaches to pursue multiple premiums: a combination approach (market portfolio plus factor portfolios) and a fully integrated approach. We evaluate the two approaches via multiple lenses: pursuit of higher expected returns, distribution of over- and underweights, turnover, and costs. Our analysis shows the integrated approach can lead to greater reliability of outperformance, better risk control, and lower costs. These benefits are critical to an efficient pursuit of multiple premiums and cannot be replicated through combination approaches.

Green Investing: Impact of Pro-environmental Preferences on Stock Market Valuations During Turbulent Periods

The study addresses the growing popularity and need of green investing. Green investing have been shown to churn lesser yields and underperform general market portfolios. Rapid growth of green bonds, green funds and green theme indices worldwide indicate towards the growing segment within investment community. The ethical screens lead to crunching of investable universe as a result such funds are expected to lose on diversification benefits. The study attempts to investigate the performance of green and non-green portfolios during the crisis and validate the differential impact of crisis on their demand. It further examines the impact of market cycles on the returns of portfolios. The period is classified into pre-crisis, crisis and post-crisis period. Asset pricing models believed to explain the returns on well diversified market portfolio have been applied on constructed green and non-green portfolios to measure the abnormal return. Green portfolios are noticed to be picking pace and outperforming market after the crisis surpassed. Indian investors are not penalizing companies for their green initiatives and such initiatives are believed to drive demand for the stock.

A novel LASSO – TLBO – SVR hybrid model for an efficient portfolio construction

In this study a LASSO – TLBO – SVR hybrid model is used for portfolio construction. Relevant economic parameters are determined and used for stock selection. Along with stock selection, weights for the stocks are obtained by solving a portfolio optimization problem using three methods: GRG Nonlinear, Evolutionary method based on Genetic Algorithm, and Equal weight method. The portfolio return in the proposed model is compared with the return of the Indian market portfolio (NSE and BSE). It is observed that the proposed model outperforms the market portfolio.

Investors’ Reactions to Extreme Events in the Hungarian Stock Market

This paper examines investors’ reactions to extreme events in the Hungarian stock market. We seek to answer the research question whether following extreme events any overreaction of investors can be observed on the Budapest Stock Exchange. With a view to answering the research question, we identify extreme events based on extreme returns on the market portfolio and then – using an event study – we examine abnormal returns on winner and loser equities. After examining investors’ reactions, we inspect the performance of the contrarian strategy in the created event windows. The main result of our research is the presentation that – based on the analysis of the differences between the average cumulative abnormal returns after extreme events – investor overreactions can be observed in the Hungarian stock market. The loser portfolios relating to extreme events significantly outperform winner portfolios connected to the event. The excess return of the contrarian strategy cannot be attributed to differences in the market risk of winner and loser portfolios. The excess return of the strategy can be shown only under tighter extreme value thresholds. The clustering of the event windows with short-term reversal, high market volatility and extreme events is beneficial to the performance of the contrarian strategy. In addition, our research also shows that the purchase of loser portfolios or the development of a contrarian strategy after extreme events may generate profit for investors, since after extreme events the loser portfolios usually beat the market on a horizon of 21 days.

Comparison of profits of effective portfolios with non-effective portfolios taking into account the fuzzy approach

Purpose: The aim of the article is to compare the results of the constructed effective portfolios and non-effective portfolios build on the basis of the value of the indicator constituting a synthetic assessment of decision variants. Design/methodology/approach: The article uses the multi-criteria TOPSIS method in the standard and fuzzy approach. It was used to evaluate listed companies that were examined in terms of selected fundamental and market characteristics. Taking into account the fuzzy method made it possible to treat the values of criteria from three years as triangular fuzzy numbers, and the values of the measure on the basis of which the ranking was created were also used to build non-effective portfolios. Findings: A multi-criteria evaluation of selected listed companies was performed and, on the basis of the obtained rankings, the sets constituting the basis for the construction of effective and non-effective portfolios were selected. The designated effective portfolios (after pre-selection using the FTOPSIS method) were in most cases more profitable than the market portfolio, while the non-effective portfolios, using TOPSIS as the pre-selection method, were (with one exception) more profitable than the effective portfolios. Research limitations/implications: It was not possible to unequivocally recommend the approach used, although the results appear promising. Practical implications: Taking into account the proposed approach, one can methodically build more profitable and more attractive portfolios. Originality/value: Non-standard approach to criteria assessments and the use of metacriterion values to determine the portfolio structure. The considerations may be of interest to stock market investors.

Optimizing the True Market Portfolio

Optimizing the True Market Portfolio

Index-Linked Trading and Stock Returns

I consider a model of index-linked trading in which a fraction of investors trade an index product that holds the market portfolio (e.g., an ETF). The remaining investors build portfolios by evaluating stocks individually. Investors are equally informed and choose portfolios to maximize their expected utility. In equilibrium, price impact from trading the index product is not equal across stocks. Index-linked trade generates cross sectional differences in returns and volatilities. Furthermore, uncertainty about indexing demand generates risk premiums in expected returns and their magnitudes depend on firm fundamentals. The findings lend theoretical support to existing studies and provide new predictions.