我国开放式基金的风险度量模型研究

开放式基金作为一种收益共享、风险共担的集合投资工具,日益受到投资者的青睐.本文首先对开放式基金传统的风险度量方法,以及Bangia、Diebold、Schuermann&Stroughair模型、Hisata&Yamai的L-VaR模型和Shamroukh的流动性风险调整VaR模型进行了综述,指出其适用性与局限性.在此基础上,提出改进的开放式基金流动性风险度量指标,通过改进的指数化换手率来避免因换手率的差异而导致流动性风险测量的失真,构建我国开放式基金的资产流动性风险价值和条件风险价值度量模型.同时,考虑股票停牌、权重股等因素,在实证中反映我国开放式基金的流动性风险,形成基于流动性风险调整的开放式基金资产变现方法.     

偏股型开放式基金“赎回悖论”的动态特征及申购异象

本文对偏股型开放式基金赎回悖论进行了系统研究,修正了传统的单期静态"赎回悖论",采用超额收益来评价基金业绩,根据月度面板模型分析了业绩对基金赎回的多期、动态影响,实证表明:基金当期业绩存在较强"赎回悖论",但历史业绩并不存在"赎回悖论",基金的历史业绩越好越能促进资金流入,且赎回悖论仅存在于老基金。为了进一步探索"赎回悖论"动态性的根源,作者引入SVAR模型分别分析了申购、赎回对业绩的多期脉冲反应,发现投资者在赎回行为上表现出相当的理性,并不存在处置效应,"赎回悖论"的根源在于投资者申购行为的异常。投资者反向选择策略、投资者对新基金的偏好以及基金市场的快速扩张是造成申购异象的直接原因。     

DIVERSIFICATION GAINS FROM INCLUDING REAL ESTATE IN MIXED-ASSET PORTFOLIOS*

Diversification gains in mean-variance efficiency derived from including real estate in financial asset portfolios are examined. Optimal financial and mixed-asset portfolios were generated by selecting from an investment universe including several distinct financial and real estate media. Deficiencies of previous studies were overcome by employing data with improved representativeness and comparability. The efficient mixed-asset portfolios dominated the efficient financial asset portfolios implying that purely financial asset diversification is inefficient. The optimal mixed-asset portfolio prescribed that approximately two-thirds of the investment wealth be allocated to real estate and one-third to the financial media.     

开放式基金经理惯性投资行为研究

本文选取上海与深圳两个证券市场2004年1月至2007年3月共52只开放式基金及其重仓持有的126支股票为研究对象,考察中国开放式基金经理惯性投资行为的特征及获利成因。研究表明,中国开放式基金经理大多倾向于采取惯性投资策略。并且通过比较分析发现,开放式基金经理对个股特征的信息反应不足,对相对惯性反应过度。本文从开放式基金的委托代理关系出发,基于经济学理性人的假设,为基金经理采取惯性投资行为及惯性策略的获利成因提供了理论解释。     

耦合风险视角下基于GARCH-Copula模型的基金组合风险研究

在资本市场不断多样化的投资方式中, 投资组合以其相对稳定的风险与收益而得到广泛应用, 其中基金组合凭借在收益一定的情况下的低风险成为投资者关注的热门品种.传统的投资组合研究大多只考虑市场风险的影响, 忽略了信用风险的耦合效应, 从而往往导致对组合总体风险的低估.首先借助于GARCH模型获得边缘分布, 然后选择Copula函数刻画各基金之间的相关结构, 建立联合分布模型, 进而采用Monte Carlo方法模拟生成基金组合中各基金的收益率序列, 最后根据损失函数计算基金组合的风险价值.实证结果表明, 市场风险大的基金组合其信用风险不一定大, 并且基金组合能有效分散基金风险.同时, 耦合风险视角下基金组合的CVaR值大于市场风险视角下的CVaR值, 耦合风险能更好地衡量基金组合的风险.另外, Student t-Copula模型较之其它模型能更好地刻画耦合风险的联合相依结构.     

基于SKT-ARFIMA-HYGARCH-VaR模型的股票型基金投资风格漂移风险测度研究

投资风格漂移是把双刃剑,基金在获取短期超额收益的同时,其背后也折射出巨大的漂移风险。本文以2004年成立的8只开放式股票型基金为研究样本,在量化基金投资风格漂移收益及分析其序列呈尖峰、厚尾与有偏特征的基础上,通过引入skt分布来刻画新生变量的分布,构建ARFIMA-HYGARCH-VaR模型来测度基金投资风格漂移风险值,并与skt分布下的RiskMetrics及GARCH族等5种VaR模型的风险测度能力做了比较实证分析,同时对各种VaR模型进行失败频率回测检验与动态分位数测试。研究结果表明:在不同显著性水平下,skt分布下的各种模型基本都有较好的风险测度能力,但ARFIMA-HYGARCH模型的VaR风险测度更加精确与稳定;Person吻合度检验也证实了skt分布能较好刻画投资风格漂移日收益序列的分布。本研究为控制较严重的投资风格漂移及规范基金产品创新设计与发行无疑具有重要的理论价值与现实意义。     

基于行为金融的开放式基金绩效评价模型

考虑决策者的有限理性,在行为金融范式下研究了开放式基金绩效评价问题.利用相对财富和习惯形成效用函数,描述了开放式基金管理者的投资组合决策行为;引入均值-熵度量开放式基金风险,建立了一种行为证券组合模型;以此为内核,研究提出了B-Morningstar风险评价模型;应用模拟分析结果表明,基于行为金融的B-Morningstar模型能够有效逼近其实际绩效水平.     

中国投资基金波动择时能力的实证研究

投资基金的择时能力是基金绩效评价的核心内容。本文通过引入收益择时因子改进了Busse的波动择时模型,并以此为工具从波动时变性的角度对我国证券投资基金的择时能力进行了实证研究。实证结果表明,不仅中国证券投资基金具有较为显著的波动择时能力,开放式基金的波动择时能力强于封闭式基金;而且改进的波动择时模型优于Busse波动择时模型。     

Inadvertent Systemic Risk in Financial Networks: Venture Capital and Institutional Funds

This paper set out to explore if the observed structure of VC syndication is conducive to pseudo-diversification in the portfolios of the VCs' sources of funds; the institutional fund managers. One hypothesis is tested that states that the observed investment network is significantly riskier than we would expect in a random allocation of risk.Data are employed on the syndication of 20 UK-based VCs, in the 11 years from 1993–2003, along with their interactions within that period with 73 different institutional funds. The hypothesis is tried by means of a z-test developed from the comparison of observed risk scores and the mean of a population of risk-proxies. This population is derived with randomised models.The findings are consistent with the observed structure of VC syndication and institutional fund-VC interactions being conducive to less diversification than expected, particularly where institutional funds invest in just two VCs. This result extends prior research. Chiefly, the study explores a gap in portfolio theory; with mutual dependency between financial agents, risk can be pseudo-diversified, affecting all parties. The data examined in this study relates VC syndication to ineffectiveness in reducing portfolio risk, in contrast with its established association to risk mitigation. Also, it is suggestive of social structure within the VC community that is replicated in interactions with both ventures and institutional fund managers. A full understanding of VC syndication and investment risk should extend beyond its prior focus on VC firms and investee ventures, and also encompass the source of funds.This paper uses case studies and a statistical model to explore the limitations of portfolio theory in the presence of investment networks with interacting agents. The research highlights that such investment networks create a kind of systemic risk that is neither particularly rare nor without disastrous precedent.     

相对业绩对投资基金风险承担行为的影响研究

本文把投资基金市场视为一系列的"联赛"建立了一个博弈模型,从理论上研究了相对业绩对投资基金风险承担行为的影响。在模型中,两个年中业绩不同的基金为了在年末即"联赛"结束时获得更多新的资金流入从而获得更多的报酬而相互竞争。与人们的直觉相反,我们发现在年末时年中业绩较好的基金反而比年中业绩较差的基金更可能选择风险水平较高的投资组合。而且,年中业绩的差距越大、风险资产的收益越高、波动越低,在年末时年中业绩较好的基金选择风险较高的投资组合的概率越大;相应地,在年末时年中业绩较差的基金选择风险较高的投资组合的概率越小。最后,我们运用博弈原理和行为金融理论对这些结论作了解释。     

银行间资产清算顺序优化与风险传染免疫机制

银行间交叉持有同业存款时,风险共担和传染是可能的。银行间市场结构的不同会对风险共担和传染产生影响,本文采用三阶段流动性偏好模型的一般分析框架,讨论了应对危机时银行微观层面的资产清算顺序的异同对于银行系统脆弱性的不同影响,并从合作博弈的视角探讨了"货币池"风险免疫的可能性。研究发现:在不存在银行资产信息不对称的条件下,当问题银行流动性波动足够大(ε>ε) ,银行间风险传染可能难以避免,而当流动性短缺ε在区间[ε,ε]内,银行间的合作博弈效果最优,风险传染可以在很大程度上避免。银行间市场的"货币池"免疫结构模式可以实现风险分担和防范银行间风险传染,从微观层面提供了一种银行间市场危机传染的内生免疫机制。     

Efficiency of well-diversified portfolios: Evidence from data envelopment analysis

In this work, we evaluate eight exchange traded funds (ETFs) and their benchmark index (the KOSPI 200 Index), based on the Sharpe ratio and the Treynor ratio and find that the performance of these well-diversified portfolios are quite poor relative to individual stocks. Investors׳ preference to avoid the well-diversified portfolios would be related to this poor performance. However, we empirically show that ETFs and the KOSPI 200 Index are the most efficient investment instruments with respect to the new performance measure designed on the basis of the data envelopment analysis (DEA) methodology. Examining the panel data over the period between 2003 and 2014 indicates that well-diversified portfolios improve the efficiency by adjusting the input variables (σ and β). Furthermore, they do so more effectively as they mature.     

双渠道风险传染下银行系统稳定性分析

随着金融危机的频率和范围的不断扩大,银行系统性风险的研究越来越受到重视。针对银行业系统性风险,构建银行同业拆借（直接传染渠道）、银行共同持有资产（间接传染渠道）的双渠道风险传染网络模型。该模型引入了宏观经济波动带来的投资风险,并允许银行通过贬值出售资产来弥补流动性,这更真实地反映了银行系统的操作规则。研究结果表明,在各种经济因素波动情况下,平均储蓄量、储蓄的波动幅度、投资的收益率、存款准备金率以及储蓄利率等对银行系统稳定性的有较大影响,并进行了定量分析。该研究为定量研究宏观经济波动下银行系统性风险问题提供了方案,并为决策者和监管部门防范银行系统性风险提供了参考。     

Tracking and outperforming large stock-market indices

Enhanced index-tracking funds aim to achieve a small target excess return over a given financial benchmark index with minimum additional risk relative to this index, i.e., a minimum tracking error. These funds are attractive to investors, especially when the index is large and thus well diversified. We consider the problem of determining a portfolio for an enhanced index-tracking fund that is benchmarked against a large stock-market index subject to real-life constraints that may be imposed by investors, stock exchanges, or investment guidelines. In the literature, various solution approaches have been proposed to enhanced index tracking that are based on different linear and quadratic tracking-error functions. However, it remains an open question which tracking-error function should be minimized to determine good enhanced index-tracking portfolios. Moreover, the existing approaches may neglect real-life constraints such as the minimum trading values imposed by stock exchanges or may not devise good feasible portfolios within a reasonable computational time when the index is large. To overcome these shortcomings, we propose novel mixed-integer linear and quadratic programming formulations and novel matheuristics. To address the open question, we minimize different tracking-error functions by applying the proposed matheuristics and exact solution approaches based on the proposed mixed-integer programming formulations in a computational experiment using a set of problem instances based on large stock-market indices with up to more than 9,000 constituents. The results of our study suggest that minimizing the so-called tracking error variance, which is a quadratic function, is preferable to minimizing other tracking-error functions.     

中国开放式基金市场波动性的实证研究

通过对中国开放式基金市场整体波动性进行全局的静态分析,给出了其波动特征的全景式描述.从动态的视角出发,运用滚动样本的检验方法刻画了开放式基金市场波动特征(包括杠杆效应、风险溢价效应和波动持续性)的时变性及演变规律.     

基于概率权重函数和随机占优准则的开放式基金评级

传统的开放式基金评级方法存在两个缺陷,首先是忽视了现实中投资者是如何做决策的,假定投资者对利益和损失的主观态度相同;其次是忽略了现实的样本性质,假定随机收益的样本达到渐近正态的规模。通过期望效用的高阶泰勒序列展开建立超额收益的高阶矩和效用函数的关系,以高阶矩为约束条件估计样本的经验概率,再对经验概率进行决策权重调整。在此基础上,通过扩展夏普比和应用随机占优准则进行基金评级,并对645种开放式基金进行了案例分析。     

Rapid Trading bei deutschen Aktienfonds: Evidenz aus einer großen deutschen Fondsgesellschaft

This paper is the first to examine rapid trading among German equity mutual fund investors. Using data on inflows and outflows provided by a large German mutual fund company for all of its equity funds, we find strong evidence for rapid trading. It is particularly pronounced for small funds, risky funds, funds with low nominal prices, and international funds. However, we find no evidence of market timing activities. Furthermore, unlike in the US, rapid trading is less pronounced for funds with high loads. This shows that rapid trading among German fund investors is not explained by churning due to brokers’ advice. Rather, our results are consistent with the view that some investors use mutual funds for short-term, speculative purposes. The funds among which we observe the strongest rapid trading show lottery-like characteristics. Regarding fund performance, we find (at most) only very weak evidence for a negative impact of rapid trading on fund performance before the fund scandal of 2003, and no evidence afterwards.     

What makes search fund entrepreneurship different in Europe?

Ownership transition is an increasingly relevant decision in small businesses because millions of owners in the largest world economies are reaching retirement age without a successor. As a result, entrepreneurship through acquisition—becoming an entrepreneur through the acquisition of an existing business and growing it much like a startup—is likely to accelerate in the coming years. In contrast to traditional entrepreneurship, where the entrepreneur comes up with an idea and then grows it into a company, the idea of entrepreneurship through acquisition is embedded in the acquired company. In this article, we share our findings from a research project that tracked first-time entrepreneurs looking to acquire businesses in four European countries. These entrepreneurs put in “sweat equity” and used the “search fund” model, whereby investors funded their search expenses and provided funds for an acquisition. However, implementing the search fund model, originally created in the United States, was not straightforward in Europe. Search funders faced novel challenges in investor-entrepreneur (i.e., principal-agent) relationships and the search process. Our study identifies these challenges, the responses from our search fund sample, the lessons learned, and a novel framework to conceptualize a search fund playbook specific to Europe. These experiences hold valuable lessons for those who pursue entrepreneurship through acquisition and help stimulate new research questions for scholars.     

基于UPM-LPM的增强指数投资策略

增强指数投资策略的理念是基于部分成份股构建指数跟踪组合,以期在跟踪指数趋势的同时,获取超出指数平均收益的超额收益。本文将指数收益率作为目标收益,拓展经典下偏矩（Lower Partial Moment,LPM）的概念,使其适应于增强指数投资策略建模,同时给出上偏矩（Upper Partial Moment,UPM）的定义,进而构建基于UPM-LPM之比的增强指数模型。为解决模型的求解复杂性和高维投资组合的"维数灾难"问题,本文运用非参数核估计方法直接得到跟踪组合的密度函数,进而得到跟踪组合的LPM和UPM的解析表达式,避免对组合中各资产之间的高维联合分布进行估计,大幅度降低了估计的维度,克服"维数灾难"问题。而且LPM和UPM的核估计量是组合头寸的光滑函数,具有任意阶导数,便于优化问题求解。最后,本文运用沪深股票市场上五个常用指数及其成份股数据,检验模型在实际金融市场中的表现,结果表明：本文提出的增强指数模型能够战胜指数,同时实现跟踪指数趋势并获取稳健超额收益的目标。     

条件自回归expectile模型及其在基金业绩评价中的应用

本文研究了日收益率之下开放式基金的业绩评价和检验问题,提出了改进的条件自回归expectile（CARE）模型并应用到基金业绩评价的问题研究中。首先运用非对称最小二乘法（ALS）对动态的CARE模型进行半参数估计,得到样本基金收益率序列的VaR值和ES值。其次,使用计算结果对样本基金的日收益率进行风险调整,得到基于VaR和ES修正的Sharpe比率。最后,在实证研究中,本文使用传统的Sharpe比率、基于VaR和ES的Sharpe比率对我国56只开放式基金在2005-2011年间的业绩进行了实证分析,结论显著证明了CARE模型在极端风险度量上更精确,在基金评价和检验中的应用中是可行的。