上海股票市场的分形特征实证研究

基于重标极差(简称R/S)分析方法,文章研究了上海综合指数序列在我国实行股市涨跌停政策后的分形特征。通过计算Hurst指数,验证了上证综指的长记忆性的存在性,并得出大约460个交易日的平均循环长度,表明上海股票市场具有明显的分形特征。     

基于R/S方法的沪深两市融资融券余额时间序列分析

本文运用分形R/S分析法研究我国融资融券余额分形结构特征,通过计算发现:沪市融资融券余额同期普遍高于深市,并都在第690天左右迅速上升,这是由沪、深两市融资融券扩容引起的;沪市和深市融资融券余额波动都不是随机游动,具有长记忆性和关联性;沪深两市的融资融券余额数据都观察不到平均循环周期等分形特征,可能是选取的样本数据不够所致。     

股市分形投资策略及其有效性研究

证券市场的分形现象已得到国内外大量文献证实。本文运用经典R/S、修正R/S、V/S和修正V/S分析法,引入并行计算的原理来简化数据计算,对我国上证综指、深证成指和贵州茅台股价序列的分形特征进行检验并予以比较。结果发现：上述四种分析法均能得出上证综指、深证成指和贵州茅台股价序列存在一定程度的持续性分形特征的结论;V/S分形策略和修正V/S分形策略的投资效果与基准投资策略相比均是有效的,而经典R/S分形策略在股价处于稳定上升行情时才能获得较好的投资收益。因此,修正V/S分形策略相比其它三种分形策略能够获得更稳定的投资收益。     

基于分形理论的国际金价波动长记忆性识别及预测研究

分形理论为国际金价定量描述提供了新的研究思路.研究结果表明,识别长记忆性时,V/S方法最贴近实际,计算出的Hurst指数证实了国际黄金现货(周线/月线)存在着显著的长记忆性,表明黄金市场不是弱势有效的,因此在国际金价预测中运用统计分析是有效的;随后通过分数差分将长记忆识别与分形预测模型有机联结了起来,构建的ARFIMA、FIGARCH与ARFIMA-GARCH等模型能够很好地刻画国际金价的内在波动规律,具有良好的定量预测功能.     

基于多重分形的我国股票波动特征研究

本文对上证指数收盘指数的收益率进行统计性描述,发现其呈现"尖峰胖尾"现象;采用Hurst指数检验法,运用软件分析出上证指数存在多重分形波动特征。并采用多重分形区趋势法(MF-DFA法),做出上证指数收益率序列的多重分形谱f(α)与奇异指数α的关系图,得出我国股票存在多重分形现象,有着显著长记忆性,且效果图优于文[5],进而说明时间的选取影响着分形效果。     

我国股债汇风险点的长记忆性及关联性研究

本文以2010年6月21日～2019年4月30日期间的上证综合指数、上证国债指数以及人民币兑美元汇率的收益率为样本,基于ARFIMA-HYGARCH模型分别对我国股债汇风险点的长记忆特征进行刻画,并在此基础上构建三元VFIAR-DCC-HYGARCH模型,旨在探究各自间的关联性问题。结论如下:股市收益的长记忆性不显著,而波动存在显著的长记忆特征;债市和汇市的收益与波动存在显著的双长记忆特征;三大风险点间的关联程度均较低,但具有很强的波动时变性,其中股市与债市、债市与汇市表现为正相关关系,股市与汇市表现为负相关关系。基于以上结论,本文为如何有效防范金融风险提出了相应的建议。     

基于R/S分析的股票网络分形特征研究

该文基于R/S分析从两个不同的角度来分析股市的分形特征:一是从不同跨度的时间序列角度,通过选取不同的时间序列,构造以月、周、日不同时间跨度的股票网络,分析其标度不变性;二是从不同数量股票节点的角度,选取不同数量的股票来构建网络,主要分析的是自相似特性。选取上海A股的历史数据,对市场的分形结构进行了实证研究。     

基于R/S分析的股票网络分形特征研究

该文基于R/S分析从两个不同的角度来分析股市的分形特征:一是从不同跨度的时间序列角度,通过选取不同的时间序列,构造以月、周、日不同时间跨度的股票网络,分析其标度不变性;二是从不同数量股票节点的角度,选取不同数量的股票来构建网络,主要分析的是自相似特性.选取上海A股的历史数据,对市场的分形结构进行了实证研究.     

基于R/S分析的我国外汇市场分形特征研究

为了研究人民币汇率序列的基本特征,更好地分析和预测未来外汇市场行情的变化趋势,本文以人民币对美元、欧元和日元汇率的每日中间报价为研究对象,价格包含了2008年2月2日至2014年2月1日6年的逐日资料,利用R/S分析实证研究,结果表明我国外汇市场存在分形特征,且人民币对美元的汇率序列对应的平均循环周期比另两种汇率长,这进一步说明2007年美国金融危机的爆发对我国外汇市场的长期记忆性的影响颇大。     

现行汇率机制下人民币汇率收益率及波动率中有双长期记忆性吗?北大核心CSSCISSCI

本文基于经典R/S分析、修正R/S分析、GPH检验以及ARFIMAFIGARCH模型估计等方法的实证研究表明:首先,与ARFIMA-FIGARCH模型相比较,基于经典R/S分析方法得到的实证结果误差较大,而GPH检验方法又低估了时间序列条件方差过程中的长期记忆性行为。其次,在日元/人民币、欧元/人民币以及英镑/人民币汇率中间价对数收益率序列当中几乎都不存在明显的长期记忆性效应,但是在其波动率序列当中却都存在着极为显著的强长期记忆性效应,即人民币汇率中间价对数收益率及其波动率当中不具有双长期记忆性效应。再次,Student-t分布和GED分布能够比正态分布更好地刻画人民币汇率中间价对数收益率序列的"尖峰厚尾"分布特征,但是与GED分布相比较,Student-t分布更优。最后,自步入2012年以来,日元/人民币和英镑/人民币汇率中间价均呈现下降的迹象,欧元/人民币汇率中间价呈现攀升的征兆,而三者收益率序列的波动性均表现出小幅震荡的低位徘徊。但是需要注意的是,在金融危机中后期,人民币汇率中间价都表现出剧烈震荡的态势,其收益率的波动性也极为显著,因此在未来一段时期内人民币汇率中间价依然具有出现宽幅波动的较大可能性。     

上海金属期货市场的非线性波动特征研究

期货市场是一个典型的非线性动力系统,通过对上海期货交易所(SHFE)的铜、铝期货合约进行非线性波动特征检验,采用基于GED(广义误差分布)的GARCH族模型考察期货收益率的ARCH效应、杠杆效应,并用R/S分析法检验期货收益率和波动率的长期记忆性,得到的实证结果表明:铜、铝期货价格波动有明显的集丛性,铜期货收益率波动没有"杠杆效应",而对铝期货来说,"利好"对条件方差的冲击大于"利空"的冲击.R/S分析结果显示:铜、铝期货收益率均呈现长期记忆性,铜期货有一个约43个日历月的非周期循环,而铝期货并没有明显的非周期循环.更重要的是,实证结果表明期货收益波动率有明显的长期记忆性,因此,在对期货市场波动率建模时应充分考虑这一点.     

基于重标极差法(R/S)对金融市场非线性动力学特性的解构

本文从四个方面就R/S分析法及其在金融市场中的应用进行了解构:(1)R/S法的基本要点和具体操作步骤;(2)运用R/S法分析金融市场非线性特性和演化规律的动力学意义;(3)R/S分析法对时间序列具有普适性;(4)提高R/S法有效性的措施。     

上海股票市场的分形特征研究

本文对有效市场假说和分型市场假说的基本理论做了介绍,对上海证券市场的分形结构进行了研究,并对上证指数收盘价的日数据和周数据进行R/S分析并计算Hurst指数,通过对比发现,上海股票市场不属于EMH所描述的有效市场,而是具有自相似性、状态持续性、长期记忆周期等明显的分形特征。     

非线性、分形与期锌市场价格

从非线性角度研究期锌市场,运用R/S分析法对期锌市场进行分析,发现期锌市场的Hurst指数为0.6183,其价格收益率序列是分维时间序列,具有分形结构,维数为1.6174。期锌市场的平均周期长度为176天,具有强持续性和相关性。关联系数为19.47%,远远大于国外相关市场。在风险方面,期锌市场的风险比期铜市场的要小,而比股票市场的风险要大。     

Dependence and mean reversion in stock prices: The case of the MENA region

This paper provides empirical evidence on the long memory behavior of the stock markets of Egypt, Jordan, Morocco, and Turkey. To test for long memory in the returns and volatility, we employ the modified rescaled range statistic R/S proposed by Lo [Lo, A.W., 1991. Long-term memory in stock market prices. Econometrica 59, 1279–1313] and the recently proposed rescaled variance V/S statistic developed by Giraitis et al. [Giraitis, L., Kokoszka, P.S. Leipus, R., Teyssiere, G., 2003. Rescaled variance and related tests for long memory in volatility and levels. J. Econ. 112, 265–294]. Further analysis is conducted by employing the ARFIMA (p, d, q) model to estimate the long memory parameters. Egypt and Morocco show evidence of long memory in the return series, while Jordan and Turkey display negative persistence. For the volatility series, long memory is conclusively demonstrated for all markets. Then, we compare the forecasting performance of ARMA and ARFIMA models and find that the ARFIMA model outperforms in out-of-sample forecasting of the markets. Our results should be useful to regulators, practitioners and derivative market participants, whose success depends on the ability to forecast stock price movements in these markets.     

The risk in hedge fund strategies: Theory and evidence from long/short equity hedge funds

Theory suggests that long/short equity hedge funds' returns come from directional as well as spread bets on the stock market. Empirical analysis finds persistent net exposures to the spread between small vs large cap stocks in addition to the overall market. Together, these factors account for more than 80% of return variation. Additional factors are price momentum and market activity. Combining two major branches of hedge fund research, our model is the first that explicitly incorporates the effect of funding (stock loan) on alpha. Using a comprehensive dataset compiled from three major database sources, we find that among the three thousand plus hedge funds with similar style classification, less than 20% of long/short equity hedge funds delivered significant, persistent, stable positive non-factor related returns. Consistent with the predictions of the Berk and Green (2004) model we find alpha producing funds decays to “beta-only” over time. However, we do not find evidence of a negative effect of fund size on managers' ability to deliver alpha. Finally, we show that non-factor related returns, or alpha, are positively correlated to market activity and negatively correlated to aggregate short interest. In contrast, equity mutual funds and long-bias equity hedge funds have no significant, persistent, non-factor related return. Expressed differently, L/S equity hedge funds, as the name suggests, do benefit from shorting. Besides differences in risk taking behavior, this is a key feature distinguishing L/S funds from long-bias funds.     

Legality and venture capital exits

This paper introduces an analysis of the impact of Legality on the exiting of venture capital investments. We consider a sample of 468 venture-backed companies from 12 Asia-Pacific countries, and these countries' venture capitalists' investments in US-based entrepreneurial firms. The data indicate IPOs are more likely in countries with a higher Legality index. This core result is robust to controls for country-specific stock market capitalization, MSCI market conditions, venture capitalist fund manager skill and fund characteristics, and entrepreneurial firm and transaction characteristics. Although Black and Gilson (1998) [Black, B.S., Gilson, R.J., 1998. Venture capital and the structure of capital markets: banks versus stock markets. Journal of Financial Economics 47, 243–77] speculate on a central connection between active stock markets and active venture capital markets, our data in fact indicate the quality of a country's legal system is much more directly connected to facilitating VC-backed IPO exits than the size of a country's stock market. The data indicate Legality is a central mechanism which mitigates agency problems between outside shareholders and entrepreneurs, thereby fostering the mutual development of IPO markets and venture capital markets.     

Information and capital asset pricing

Investors in a market frequently update their diverse perceptions of the values of risky assets, thus invalidating the classic capital asset pricing model's (CAPM) assumption of complete agreement among investors. To accommodate information asymmetry and belief updating, we have developed an empirically testable information-adjusted CAPM, which states that the expected excess return of a risky asset/portfolio is solely determined by the information-adjusted beta rather than the market beta. The model is then used to analyze empirical anomalies of the classic CAPM, including a flatter relation between average return and the market beta than the CAPM predicts, a non-zero Jensen's alpha, insignificant explanatory power of the market beta, and size effect.     

基于行为金融的银行间债券交易行为研究

本章主要从数量的角度分析了银行间债券市场的主体交易行为。由于传统金融市场理论与银行间市场的实际情况存在不符的情况,作者试图用行为经济学理论来解释银行间市场的主体交易行为。由于数据方面的原因,本实证分析仅局限于银行间现券交易。实证结果显示,银行间市场不同主体之间的行为存在显著的差异性。最后,论文引入行为因子,对传统债券定价模型进行修正。     

The impact of macroeconomic and regulatory factors on bank efficiency: A non-parametric analysis of Hong Kong’s banking system

This paper assesses the relative technical efficiency of institutions operating in a market that has been significantly affected by environmental and market factors in recent years, the Hong Kong banking system. These environmental factors are specifically incorporated into the efficiency analysis using the innovative slacks-based, second stage Tobit regression approach advocated by Fried et al. [Fried, H.O., Schmidt, S.S., Yaisawarng, S., 1999. Incorporating the operating environment into a nonparametric measure of technical efficiency. Journal of Productivity Analysis 12, 249–267]. A further innovation is that we also employ Tone’s [Tone, K., 2001. A slacks-based measure of efficiency in data envelopment analysis. European Journal of Operational Research 130, 498–509] slacks-based model (SBM) to conduct the data envelopment analysis (DEA), in addition to the more traditional approach attributable to Banker, Charnes and Cooper (BCC) [Banker, R.D., Charnes, A., Cooper, W.W., 1984. Some models for estimating technical and scale efficiencies in data envelopment analysis. Management Science 30, 1078–1092].The results indicate: high levels of technical inefficiency for many institutions; considerable variations in efficiency levels and trends across size groups and banking sectors; and also differential impacts of environmental factors on different size groups and financial sectors. Surprisingly, the accession of Hong Kong to the People’s Republic of China, episodes of financial deregulation, and the 1997/1998 South East Asian crisis do not seem to have had a significant independent impact on relative efficiency. However, the results suggest that the impact of the last-mentioned may have come via the adverse developments in the macroeconomy and in the housing market.