各种指数基金模型的实证比较分析

在指数基金管理方面，存在着多种优化的指数投资组合的构建方法和绩效评估方法，本文以实证研究的形式，比较分析了由5种“选股”方法和5种“资金配置”方法所构成的25种投资组合在各种绩效评估方法下的表现。最终得出结论认为，在遗传算法下利用DMinMax模型配置资产权重将具有较好的投资绩效。     

Análisis de portafolio por sectores mediante el uso de algoritmos genéticos: caso aplicado a la Bolsa Mexicana de Valores

The type of industry, size of company, number of employees, etc. are variables that are considered as control variables in a large number of articles. In this research we consider the sector variable as a determinant of financial performance (Baird et al. 2012) and the risk (Artikis and Nifora, 2011) rather than as a control variable. This paper analyzes six sectors of the Mexican economy divided according to the Mexican Stock Exchange: industrial, basic consumer products, materials, non basic consumer products, telecommunications and financial services. The sample consists of Mexican companies, that is, 30 companies in the 2007-2012 period. To measure portfolio performance two classic indicators are used: (1) Jensen alpha and (2) Sharpe ratio, and also conditional metrics are used that measures the number of times the portfolio return exceeds the market average. The goal is to find a portfolio that maximizes these parameters and compare the results between the different sectors under study. Due to a nonlinear programming problem, genetic algorithms are used to obtain the optimal portfolio that maximizes these metrics. The results show a better risk-adjusted financial performance in the field of materials and financial services and a lower performance in such sectors as the industrial and telecommunications ones.     

Socially responsible and conventional investment funds: performance comparison and the global financial crisis

We investigate the performance of socially responsible funds (SRFs) and conventional funds (CFs) in different market (geographical area and class size) segments during the period 1992–2012. From an unbalanced sample of more than 22 000 funds, we define a matched sample using a beta-distance measure to match any SRF with the ‘nearest neighbour’ CF in terms of sensitivity to risk factors. Using this matching approach and a recursive analysis, we identify several switch points in the lead/lag relationship between the two investment styles over time in different market segments. A relevant finding of our analysis is that SRFs played an ‘insurance role’ outperforming CFs during the 2007 global financial crisis.     

解析凸函数的两个重要不等式

与凸函数有关的不等式是基础数学理论的重要工具,尤其在不等式的证明中发挥的作用是无可替代的.其中Jensen不等式与Hadamard不等式更是起到重要作用.Jensen不等式通常用来证明有限不等式,它是将无穷项求和与积分联系起来的重要桥梁.利用Hadamard不等式可以对两个正数的几何平均数与算术平均数加细.     

封闭式基金与开放式基金绩效对比的实证研究

近年来我国新设立的开放式基金远远多于封闭式基金。在数量迅速增长的情况下,开放式基金能否取得优于封闭式基金的绩效受到市场的普遍关注。本文选取了发行时间较早,发行规模超过20亿的15只封闭式基金和15只开放式基金,从收益率、风险调整后的绩效和选股择时能力三个方面比较了2006年1月6日至12月29日共49周开放式基金与封闭式基金的绩效。实证结果显示,封闭式基金在平均收益率和收益风险比上略高于开放式基金,但在选股和择时能力上并不存在显著的差异。     

我国开放式基金的运营费用与基金业绩实证研究

文章研究我国开放式基金运营费率的影响因子,以及其与基金业绩表现之间的关系,其中用Jensen’s alpha作为基金业绩的衡量指标,体现基金管理人的综合管理能力。通过对2009年运行的开放式证券投资基金进行实证分析,结果表明:(1)基金的运营费率与其业绩表现呈现非线性的显著负相关关系,基金的业绩越高,其运营费率越低,且降低幅度趋缓,说明为了维持较高的基金业绩表现,可能需要投入更高的边际成本。(2)基金的规模越大,机构投资者持有比例越高,基金运营费率越低;债券型基金的运营费率相对较低。     

On Optimal Instrumental Variables Generators, with an Application to Hedge Fund Returns

In this paper, we propose a new benchmarking procedure lying on cumulants for computing the factor loadings in financial models of returns. We apply this technique to the well-known augmented Fama and French (J Fin Econ 43(2):153–193, 1997) model and compare it with another technique of ours based on higher moments. Our new procedure confirms the fact that the alpha is supposed to decrease when we disaggregate HFR indices to the level of individual funds while correcting for specification errors. Our new technique is therefore useful for hedge funds selection or ranking based on the alpha of Jensen corrected for specification errors. This technique will also be useful for calibrating other financial models of returns like the simple market model or the conditional alpha and beta models.

Evaluating the Performance of Investment Funds in Turkey

It is important to determine the most appropriate levels of risk and return for small investors. For that purpose, the investment funds are very important tools to create a portfolio for small investors, to deploy the potential risks in optimal proportions, and to direct investors. In this study, the performance of 83 pieces of investment funds will be evaluated which are treated in Turkey dates from January 1, 2010 to December 31, 2012 with performance evaluation methods such as Sharpe, Modigliani （M2） that is based on the standard deviation, and Treynor, T2, Jensen that is based on systematic risk （beta）, and the highest and lowest performance investment funds will be presented. The aim of the study is to examine the success of the investment fund managers whether they could estimate the course of the market well or not regarding time period. The empirical results show that the investors who invest on the funds that have negative risk premium by investing in the investment funds getting under the risk cannot get more excess return than getting the return from the risk-free interest rate as treasury bills. The result implies that it could be said that the systematic and total risks of all investment funds are low and they are not sensitive to the developments in the market, and thus, regarding funds could be called as conservative funds.     

基于詹森阿尔法的沪深300指数基金业绩评价

对目前已上市的27家沪深300指数基金,运用基于詹森阿尔法基金业绩评价方法的单因素模型和双因素模型,考察最近两年所有基金的业绩表现。得出如下结论:在一年的较长时期内,沪深300指数基金的阿尔法值未能超越市场收益;在不同时期,指数基金的业绩并不稳定;部分积极管理型指数基金仍能取得正的阿尔法值,说明我国证券市场的效率并不高。     

柯西不等式的几种证明方法

如果某一知识跟很多学科或者一个学科的很多分支有着密切联系,那么这个知识肯定是很重要的,而二次型、欧式空间内积、詹森不等式都是高等数学中代数、实函、微积分的基本内容。本文运用二次型理论、欧式空间中内积性质和詹森(Jensen)不等式三种方法证明柯西不等式,并简要说明柯西不等式与高等数学之间的联系。