A novel approach to portfolio selection using news volume and sentiment

In this study, we develop a novel approach to portfolio diversification by integrating information on news volume and sentiment with the k-nearest neighbors (kNN) algorithm. Our empirical analysis indicates that high news volume contributes to portfolio risk, whereas news sentiment contributes to portfolio return. Based on these findings, we propose a kNN algorithm for portfolio selection. Our in-sample and out-of-sample tests suggest that the proposed kNN portfolio selection approach outperforms the benchmark index portfolio. Overall, we show that incorporating news volume and sentiment into portfolio selection can enhance portfolio performance by improving returns and reducing risk.     

Skewness,sampling risk,and the importance of diversification

Recent papers have extended portfolio theory to include skewness along with mean return and variance to explain security preferences. Because the positive skewness typically present in individual assets such as stocks and call options is rapidly reduced through diversification, several authors have suggested that a preference for positive skewness can lead to antidiversification as investors attempt to capture the greatest amount of positive skew. These analyses ignore the sampling risk (the probability that the skewness of a particular portfolio of size n will be near its expected value) that exists when less than fully diversified portfolios are held.This analysis presents skewness statistics for three security populations over three market periods to illustrate the relationship between sampling risk and diversification. Small portfolios of stocks or call options are shown to possess greater expected skewness than larger portfolios for each sample period examined, but small portfolios also exhibit the greatest sampling risk for skewness. Depending upon an investor's skewness preference, some diversification in these assets appears appropriate to increase the confidence regarding the actual skewness that will be observed for a particular portfolio chosen. Expected skewness for covered call portfolios is negative for all portfolio sizes and sample periods and declines as portfolio size inreases. The elimination of sampling risk and the reduction of negative expected skewness can be accomplished through complete diversification in these assets.     

Relationship between portfolio diversification and value at risk: Empirical evidence

This research explores the risk associated with the stocks prices in the seventeen selected companies that are listed in Indian BSE (100) National as well as portfolios of investment that are constructed from these seventeen companies employed. Additionally, for considering the possibility of international diversification, construction of portfolios of investment form stock price indexes in various emerging markets and developed countries of the world is considered. Correlations for domestically as well as internationally diversified portfolios are computed to unveil the relationship between stock prices of various firms as well as domestic and internationally diversified portfolios of investments. Further, to understand the effect of diversification on the risk associated with each of the portfolios of investments employed, value at risk analysis (VaR) is undertaken for studying the benefits associated with domestic as well as international diversification (if any).The study results show that domestic diversification lowers the expected losses associated with each of the domestic portfolios of investment employed where the international diversification substantially mitigates the portfolio risks. Results from VaR analysis reveal that diversification lowers the portfolio risks and additional reduction in portfolio risks is realized by international diversification.     

The influence of strategic patterns of internationalization on the accuracy and bias of earnings forecasts by financial analysts

This paper examines how financial analysts’ earnings per share forecasts are affected by strategic patterns that multinational firms have used to expand abroad. Prior empirical studies have examined a firm's internationalization level as a one-dimensional construct involving increased task complexity for financial analysts’ forecasting and therefore resulting in lower accuracy and greater optimistic bias in earnings forecasts. In contrast, we use two strategic patterns of internationalization associated with geographic dispersion and cross-border integration to characterize a firm's international strategy, and find different empirical results using a sample of U.S. public companies with domestic and international operations. The empirical evidence suggests that geographic dispersion contributes to increases in forecasting accuracy and decreases in optimistic bias. Further, the results support that cross-border integration leads to decreases in forecasting accuracy. The two strategic patterns of internationalization are a consequence of managerial choices and therefore these results are important for managers, investors and shareholders as they help explain the linkages between international strategies and earnings forecasts by financial analysts.     

Dynamic interdependence of ASEAN5 with G5 stock markets

We find ASEAN5 and G5 stock markets are weakly linked in normal conditions. ASEAN5 markets became more connected with G5 markets during global financial crisis, with stronger conditional correlations, a higher level of risk spillover-connectedness and intensive causal risk dependence. By implications, ASEAN5 stocks are both return enhancers and risk diversifiers in boom market conditions. The diversification benefits remain even during crisis times, albeit lesser. Over the longer term, the diversification benefits of a portfolio that includes both ASEAN5 and G5 stocks are recaptured as market linkages revert to some lower levels due to decreased crisis contagion.     

Why, when, and how to diversify? A comparison between Western theories and the cognition of Chinese enterprises

This paper uses as research samples 140 papers on enterprise diversification published in top-notch Western journals, and public statements from 30 influential contemporary Chinese CEOs on enterprise diversification. Both the qualitative open coding and the qualitative factor analysis are employed to analyze the two samples respectively, and then the corresponding analysis is utilized to explore the differences between Western theories and the cognition of Chinese enterprises on the motivation (why), timing (when) and industry choice (how) of enterprise diversification. Results show that, first, both consider the motivation of diversification mainly from the perspectives of resource-based view and asset portfolio theory. However, Western theories pay more attention to the factors related to the perspectives of the resource-based theory, transaction cost theory and agency theory, while Chinese enterprises put more emphasis on those factors associated with the asset portfolio theory, government policies and institutional theory. Second, on the cognition of the timing of diversification, Western theories insist that enterprises should diversify when they meet threats, while the practice of Chinese enterprises insists that diversification should take place when enterprises have enough strength. Third, Western theories focus more on the interrelationship between the original industry and the intended industry than on the attractiveness of the intended industry, while Chinese enterprises pay more attention to attractiveness than interrelationship. Translated from Guanli Shijie 맜理世界 (Management World), 2005, (8): 94–104     

Diversification patterns and survival as firms mature

We focus on the relationship between age and diversification patterns of German machine tool manufacturers in the post-war era. We distinguish between ‘minor diversification’ (adding a new product variation within a familiar submarket) and ‘major diversification’ (expanding the product portfolio into new submarkets). Our analysis reveals four main insights. First, we observe that firms have lower diversification rates as they grow older, and that eventually diversification rates even turn negative for old firms on average (where negative diversification corresponds to exit from certain product lines). Second, we find that product portfolios of larger firms tend to be more diversified. Third, with respect to consecutive diversification activities, quantile autoregression plots show that firms experiencing diversification in one period are unlikely to repeat this behavior in the following year. Fourth, survival estimations reveal that diversification activities reduce the risk of exit in general and to a varying degree at different ages. These results are interpreted using Penrosean growth theory.     

Differencing interval and autocorrelation effects on portfolio diversification: Additive versus multiplicative assumptions

The effects of differencing interval and autocorrelation on the process of portfolio diversification are examined in detail, with both additive and multiplicative rates of return. The autocorrelation effect on portfolio diversification is not separable from the differencing interval effect. Their combined effects have a significant impact on a portfolio's residual risk. The differencing interval effect on total risk and systematic risk is also examined. For additive rates of return, the differencing interval effect on total risk is somewhat reduced by the process of portfolio diversification. For multiplicative rates of return, the differencing interval has a declining effect on total risk. Systematic risk is found to have a relatively constant relationship with the length of the differencing interval despite the fact that it is increased with the length of the differencing interval.     

Diversification potential of Asian frontier,BRIC emerging and major developed stock markets: A wavelet-based value at risk approach

This study examines the portfolio risk and the co-movements between each of the BRIC emerging and South Asian frontier stock markets and each of the major developed stock markets (U.S., UK and Japan), using the wavelet squared coherence approach as well as the wavelet-based Value at Risk (VaR) method. The results show that the co-movements and diversification benefits between these markets vary over time and across frequencies. Additionally, the co-movements are intensified in the wake of the recent global financial crisis (GFC) and the Eurozone sovereign debt crisis (ESDC). More precisely, the wavelet-based VaR ratio indicates that including a BRIC or a South Asian (particularly Pakistan and Sri Lanka at both the short- and long-term) stock market in a portfolio of the developed stock markets reduces the resulting portfolio's VaR. Specifically, adding China in the medium term to this portfolio reduces risk in the pre- and during both the GFC and ESDC periods. By assigning optimal weights to the different market assets in the portfolio formulation, the analysis thus has implications for international investors.     

Dependence of stock and commodity futures markets in China: Implications for portfolio investment

We examine the recent trends in dependence structure between the fast-growing commodity markets and the stock markets in China. We address this issue by using copula functions that allow for measuring both average and tail dependence. Our results provide evidence of low and positive correlations between these markets, suggesting that commodity futures are a desirable asset class for portfolio diversification. By comparing the market risks of alternative portfolio strategies, we show that Chinese investors can take advantage of commodity futures during different times to realize risk diversification and downside risk reduction benefits.     

Entrepreneurship: skills and financing

This article analyzes an occupational choice model with risk-averse agents who are heterogeneous in terms of skills and wealth in a setting with financial frictions. We show that high- and middle-wealth individuals endowed with a balanced portfolio of skills upgrade their skills so that the resulting portfolio of skills is more balanced and choose entrepreneurship. In contrast, middle-wealth individuals endowed with an unbalanced portfolio of skills and low-wealth individuals specialize in the skill in which they have an absolute advantage and choose paid employment. Deeper financial development, a more balanced portfolio of skills, lower entrepreneurial risk, and a higher liquidation value for projects result in more entrepreneurship and higher welfare, while wealth redistributions and financial subsidies to entrepreneurs have an ambiguous effect on welfare.     

Comparative Advantage and the Gains from Financial Trade: A Reappraisal

Emerging market crises have suggested that a national benefit‐cost assessment of external financial liberalisation could well prove unfavourable. This paper re‐examines the principle of comparative advantage in its application to financial trade to seek guidance on measures that might permit a fuller realisation of the potential benefits involved. Drawing a parallel with Balasubramanyam's work on the gains from FDI and international migration we distinguish between those arising in financial trade from the net transfer of capital, and those deriving from the contemporaneous exchange of financial claims or services of equivalent value. In the first interpretation a country's comparative advantage is manifested by its role in ‘intertemporal’ trade (as a borrower or lender). Our alternative emphasis is on the contractual risk‐return characteristics of the financial claims exchanged. This perspective is applied firstly to portfolio diversification gains arising from further international stock market integration. Secondly, price risk management for developing countries in international primary commodity trade is discussed. Both applications imply the need for significant institutional development but could realise approximately contemporaneous gains reminiscent both of those involved in merchandise trade and in the skills and product (or service) flows that Balasubramanyam has emphasised in relation to FDI and international migration.     

保险资金投资管理中的风险分散问题研究

组合投资是利用投资组合内各个风险资产之间的相关性来分散风险的,而均值—方差投资组合模型采用的相关性度量—相关系数无法准确地度量风险资产之间的相关性,这必将对组合投资的风险分散效果产生不利影响。本文提出,用理论性质更好的相关性度量来度量风险资产之间的相关性,并建立基于Kendallτ的投资组合模型。通过实证研究发现,在保险资金投资管理中,采用基于Kendallτ的投资组合模型能够取得比均值—方差投资组合模型更好的风险分散效果。     

Principal Component Value at Risk

Value at risk (VaR) is an industrial standard for monitoring financial risk in an investment portfolio. It measures potential losses within a given confidence interval. The implementation, calculation, and interpretation of VaR contains a wealth of mathematical issues that are not fully understood. In this paper we present a methodology for an approximation to value at risk that is based on the principal components of a sensitivity‐adjusted covariance matrix. The result is an explicit expression in terms of portfolio deltas, gammas, and the variance/covariance matrix. It can be viewed as a nonlinear extension of the linear model given by the delta‐normal VaR or RiskMetrics (J.P. Morgan, 1996).     

Choosing an optimal investment strategy: The role of robust pair-copulas based portfolios

This paper is concerned with the efficient allocation of a set of financial assets and its successful management. Efficient diversification of investments is achieved by inputing robust pair-copulas based estimates of the expected return and covariances in the mean-variance analysis of Markowitz. Although the whole point of diversifying a portfolio is to avoid rebalancing, very often one needs to rebalance to restore the portfolio to its original balance or target. But when and why to rebalance is a critical issue, and this paper investigates several managers' strategies to keep the allocations optimal. Findings for an emerging market target return and minimum risk investments are highly significant and convincing. Although the best strategy depends on the investor risk profile, it is empirically shown that the proposed robust portfolios always outperform the classical versions based on the sample estimates, yielding higher gains in the long run and requiring a smaller number of updates. We found that the pair-copulas based robust minimum risk portfolio monitored by a manager which checks its composition twice a year provides the best long run investment.     

Foreign exchange market liberalization and the international diversification of borrowing by Italian firms

In this article we try to assess the relative importance of real and financial determinants in firm's foreign currency borrowing by extending a model earlier developed by Kawai. We use this framework to examine the behavior of Italian firms during the 1980s. The financial components of firm's decisions are studied by means of a repeated mean-variance portfolio model based on ex ante expectation. We show that (a) the invoice currencies seem to be a good indicator of firm's real exchange risk; and (b) even at times of capital controls, corporate debt policy was affected by financial variables. The latter will become increasingly important as European financial integration moves on.     

Strategic Portfolio Management Model

Abstract

Institutional investors look forward to extra-ordinary returns in the new millennium. Yet, many have not displayed knowledge of scientific models such as modern portfolio theory, capital asset pricing model, and other financial assets investment management approaches, particularly within the local setting. They indiscriminately take risk by investing in subjectively determined options. We surveyed 44 quoted and unquoted companies, typical of emerging economies using Nigeria as a case. The test of hypotheses reveals that the firms' basis of portfolio selection is traditional. Investment risk is taken for granted. Also the homogeneity of portfolio components, though attractive in the short-run, adversely affect investment returns in the long-run. We, therefore, recommend the departmentalization and standardization of the corporate investment management process, reorientation and direction of organizational functionaries towards effective adoption of scientific approaches as integrally represented by the strategic portfolio management model, exemplified in this work.     

风险态度、金融教育与家庭金融资产选择

文章基于中国城市居民消费金融调查数据,研究了风险态度、金融教育对家庭金融资产选择和家庭金融市场参与的影响。结果发现,风险态度显著影响家庭金融资产组合分散化程度,风险厌恶程度越高,金融资产组合分散化程度越低。风险态度对家庭正规金融市场参与有显著影响,风险厌恶程度的提高会显著降低家庭在股票、基金、债券、储蓄性保险市场的参与概率,风险厌恶程度增加一单位,家庭参与股票市场的可能性会降低10.5%。风险厌恶程度对股票、基金、债券、储蓄性保险资产在家庭金融资产中的比例具有显著的负向影响。家庭的金融教育投入对风险资产持有比重条件分布的影响上,呈先上升后下降趋势,中间分位的要大于两端。文章相应的政策含义是,政府及金融管理部门需要普及金融教育知识,提高居民的金融风险认知水平,从而优化家庭金融资产选择,改善居民金融福利。     

Portfolio Optimization and Martingale Measures

The paper studies connections between risk aversion and martingale measures in a discrete-time incomplete financial market. An investor is considered whose attitude toward risk is specified in terms of the index b of constant proportional risk aversion. Then dynamic portfolios are admissible if the terminal wealth is positive. It is assumed that the return (risk) processes are bounded. Sufficient (and nearly necessary) conditions are given for the existence of an optimal dynamic portfolio which chooses portfolios from the interior of the set of admissible portfolios. This property leads to an equivalent martingale measure defined through the optimal dynamic portfolio and the index 0 < b ≤ 1. Moreover, the option pricing formula of Davis is given by this martingale measure. In the case of b = 1; that is, in the case of the log-utility, the optimal dynamic portfolio defines the numéraire portfolio.     

An item response theory approach to constructing and evaluating brief and in-depth financial literacy scales

We applied item response theory (IRT) to construct and evaluate new brief and in-depth financial literacy scales. A survey of a UK adult sample (N = 589) included 50 questions to assess knowledge about managing financial resources and competence in using personal finance-related information—including five widely used items, on interest rates, inflation, investment diversification, mortgages and bonds. IRT applied to a scale of these items identified some limitations, overcome via further iterations to construct a new brief scale with sound psychometric properties. IRT was then applied iteratively to our pool, resulting in an in-depth, 20-item scale, also psychometrically sound, covering four broad financial domains: everyday money transactions; the concept of money; borrowing; and saving and investment. Parallel 10-item sub-scales were also evaluated. The validity of the new scales was demonstrated by regression analyses which found that, controlling for demographic variables, financial literacy predicted key indicators of financial well-being.