股指期货对证券市场有效性的作用——以行为金融为视角的实证研究

股指期货能否提高股票市场的质量、改善市场的有效性,一直存在诸多争议。对市场的看法不同,使用的假设条件和验证方法不同,往往得出不同结论。文章以行为金融学为视角,运用反转投资策略,研究2011年至2013年间沪深300成分股股票能否获得超额收益。研究发现,反转投资策略可以带来超额收益,但沪深300股指期货推出后,超额收益的波动有减缓的趋势,说明中国股票市场有效性在逐步提高。     

我国封闭式基金的三因素定价模型实证研究

本文首先介绍了Fama和French的三因素模型构建方法,而后分别运用CAPM模型和三因素模型对我国封闭式基金截面平均收益进行解释,以分析和比较CAPM模型和三因素模型在国内封闭式基金定价问题上的适用性。本文的研究结果表明三因素模型明显优于CAPM模型。     

中国A股市场股票收益率风险因素分析:基于Fama-French三因素模型

本文以中国A股市场上市公司为样本,基于Fama-French三因素模型,实证分析了中国A股市场股票收益率的风险因子.研究结果表明,Fama-French三因素模型较CAPM模型能更好地解释中国A股市场的股票收益率;中国A股市场股票收益率存在规模与价值效应,股票(或股票组合)收益与公司规模呈显著负相关关系,而与公司账面市值比呈显著正相关关系.     

法玛—弗兰奇五因子模型的动态分析*

本文采用动态模型平均（dynamic model averaging,DMA）算法对法玛—弗兰奇五因子模型（Fama French five factor model,FF5模型）进行了系统性研究。基于法玛和弗兰奇（Fama and French）的数据,笔者所进行的实证分析表明：资产定价模型因子对投资组合收益的预测能力和系数是随时间动态变化的;不存在固定的因子模型能够同时解释和预测多种投资组合的收益;在对投资组合收益率进行预测时,DMA算法的预测均方误差（mean square error,MSE）显著低于固定系数的FF5模型。     

分析师的建议是否有投资价值--来自中国市场的经验数据

本文采用经验研究的方法根据2004年3月至2005年6月券商研究员给出的19310次股票投资评级检验分析师的投资建议是否有投资价值.在样本期间,分析师增持评级组合可以获得23.85%的年化超额收益率,该超额收益率在经过CAPM模型、Fama-French三因素模型和包括惯性(Momentum)因素的四因素模型风险调整后仍然显著;分析师减持评级组合的超额收益率为负值,但统计结果并不显著.研究结果支持了中国股市分析师建议具有投资价值的观点,并且为中国股市市场有效性程度提供了新的证据.     

风险或偏误？企业投资视角下股票价值效应的成因研究

本文以企业投资与股票收益模式之间的关系为切入点,就股票市场上价值效应成因的投资角度解释进行了分析,并运用GRS时间序列回归检验和广义矩横截面估计的方法对该理论解释进行了实证检验。研究发现,以投资资本比为指标所构建的投资因子．包含着与Fama—French三因素模型中账面市值比因子相近的信息,并且能够与账面市值比因子一样好地解释价值效应。该发现为撤资代价及反周期风险价格是导致价值效应的动因这一理论提供了经验证据,也为经济决策者更好地理解我国企业投资、经济周期和金融市场波动性之间的系统相关性提供了依据。     

高阶资本资产定价和中国股票市场的实证

股票的投资收益不仅仅受系统性风险的影响,其他因素的影响不容忽视。文章引入高阶资本资产定价模型,对传统的CAPM模型进行扩展,并用时间序列回归和横截面回归,参照BJS的实证检验方法,对中国股票市场进行实证分析。结果表明,加入偏度和峰度的高阶资本资产定价模型在中国股票市场具有更好的解释力。而且在这两个因素中,偏度与投资收益显著地负相关;峰度与投资收益正相关,但是相关性并不显著。     

股市中行业联动效应的实证分析——基于CAPM的空间计量模型的应用

本文基于CAPM模型,通过使用空间权重矩阵将同行业其他股票收益率的影响因素纳入了解释变量之中构建了一个收益率交互影响模型,并通过FF三因素模型从股票市场中找出公司规模和账面市值比的相关变量作为联动效应变量的工具变量,克服了联动效应变量的内生性问题。然后在此基础上分别对上证50、上证180、沪深300这三种股指所包含的股票样本进行了回归分析,证实了我国的证券市场中确实存在收益率之间的行业联动效应,并且联动反应系数大约为0.7到0.8之间。     

知情交易与中国股市博彩溢价

本文发现中国股市存在博彩（投机）溢价,且无法为Fama—French三因子模型解释。尽管在组合构造期内,博彩型股票存在显著溢价,但组合的超额收益会迅速消失,并未给投资者（或投机者）带来持续的财富效应。基于知情交易概率测度,我们进一步发现中国股市的知情交易者驱动（或引发）了博彩型股票溢价;在组合构造后的月份,并没有明显的知情交易者存在,这意味着知情交易者在基于私人信息获利之后,那些随后进入市场的投资者（动量交易者）无法获得超额收益。     

中国股票市场动量投资策略分析

本文通过构造576种动量投资策略,分析中国股票市场动量效应的特征,发现形成期为11个月,持有期为2个月的动量策略可以获得最大的月收益率:1.848%.总体来看,中国股票市场短期(一到三个月)内,动量效应和反转效应都不显著,中长期(三个月到三年)存在显著的动量效应,三年后动量效应基本消失,也不存在反转效应;随着持有期增大,动量收益呈现先增大后减小的趋势.     

The winner-loser anomaly: recent evidence from Greece

This article finds evidence of significant reversals in returns over the medium term in Greek stocks. In contrast with previous research, return reversals are more pronounced for past winners, suggesting that the market overreacts to a greater extent to good news. These contrarian returns are particularly elevated when portfolios are formed using quartiles and during tranquil and bull markets. The optimum contrarian strategy involves skipping the first 6 months of the holding period and implementing the contrarian strategy for a period of 18 months, as returns exhibit continuation followed by reversal. The profitability of the contrarian investment strategy is robust to adjustments for risk and seasonalities. It is the tranquil times and not the crisis/volatile times that generates a significant and profitable contrarian strategy. The recent credit crisis and resulting stock market falls, resulted in extreme movements in some Greek stocks and testing of the contrarian strategy problematic, especially when portfolios are decile ordered. Our findings also highlight the importance of survivorship bias and also suggest that contrarian strategies that just use market beta may be ill-equipped to take into consider extreme market movements, illiquidity and short-sales constraints.     

Investment horizon effect on asset allocation between value and growth strategies

How does the optimal risk exposure of assets change as their investment horizons increase? Does this impact investment portfolio decision-making, in particular, optimal asset allocation between value and growth strategies over various investment horizons? This paper adopts a new approach to address these questions by examining portfolio allocation between value and growth stocks over various investment horizons. This new approach is based on wavelet analysis, which decomposes the returns of a particular investment strategy across multiple investment horizons. The key empirical results show that the success of pursuing the value strategy (short-selling growth stocks and going long on value stocks) is impacted by the approach used to classify value and growth stock returns. We explore two common alternatives: Fama-French versus Standard & Poor's (S&P) 500/Barra portfolios. The results using Fama-French portfolios show that as the investment horizon increases, the optimal mean allocation of investors tilts heavily away from growth stocks, particularly for lower and moderate levels of risk aversion. Interestingly, for S&P 500/Barra portfolios the allocation weights between value and growth do not vary much.     

Performance of value- and size-based strategies in the Italian stock market

This paper investigates the performance of size- and value-based strategies in the Italian stock market in the period 2000–2018. Previous research argued the impossibility to define properly value-sorted portfolios due to the inaccuracy of book-to-market ratios available for Italian listed stocks. Using more accurate data, we implement portfolios sorting based on value and growth stocks, to assess the relevance of the value factor in the Italian stock market. We find that the capital asset pricing model fails to explain the cross-section of returns on the different strategies while the Fama and French three-factor model provides a better fit. The results show that all three factors are significant in explaining Italian stock returns during the sample period. Unlike previous studies, which either found no value effect at all or no clear-cut results when testing the book-to-market variable, we find that the value factor is statistically significant and the associated risk premium is of a considerable size.     

Global financial crisis and dependence risk analysis of sector portfolios: a vine copula approach

We use regular vine (r-vine), canonical vine (c-vine) and drawable vine (d-vine) copulas to examine the dependence risk characteristics of three 20-stock portfolios from the retail, manufacturing and gold-mining equity sectors of the Australian market in periods before, during and after the 2008–2009 global financial crisis (GFC). Our results indicate that the retail portfolio is less risky than the manufacturing counterpart in the crisis period, while the gold-mining portfolio is less risky than both the retail and manufacturing sector portfolios. Both the retail and gold stocks display a higher propensity to yield positively skewed returns in the crisis periods, contrary to the manufacturing stocks. The r-vine is found to best capture the multivariate dependence structure of the stocks in the retail and gold-mining portfolios, while the d-vine does it for the manufacturing stock portfolio. These findings could be used to develop dependence risk- and investment risk-adjusted strategies for investment, rebalancing and hedging which more adequately account for the downside risk in various market conditions.     

The Pricing of Italian Equity Returns

In this paper, we investigate the relationship between common risk factors and average returns for Italian stocks. Our research has identified the Italian stock market's economic variables by using the results from factor analyses and time series regressions. We study several multi‐factor models combining the relevant macroeconomic variables with the mimicking equity portfolios SMB (small minus big) and HML (high minus low) proposed by Fama and French (1993). The key question we want to ask ourselves, is whether the influential role of the size and book‐to‐market equity factors in explaining average stock returns can stand up well when competing with some macroeconomic factors. In other words, do stock returns carry some risk premium that is independent of either the market return or the economic forces that underlie the common variation in returns? Our empirical work estimates risk premiums using both traditional two‐pass procedures and one‐pass (full information) methodologies. We show that only the market index and variables linked to interest rate shifts are consistently priced in the Italian stock returns. The role of other factors, and in particular both the size and the price‐to book ratio, are crucially dependent on the estimation procedure. (J.E.L.: G11, G12).     

The relation between asset growth and the cross-section of stock returns: Evidence from the Chinese stock market

This study examines the effect of firm investment on stock returns by using data on the Chinese stock market. We find that stocks with higher investment experience lower future returns and there is an obvious investment effect in the Chinese stock market. The investment effect is stronger for firms that have higher cash flows, lower debt or for state-owned firms. We further explore the relation between investment and returns over the 3 years around portfolio formation. The results show that the high investment firms earn higher returns than low investment firms before portfolio formation; however the high investment firms earn lower returns than low investment firms after portfolio formation, such evidence is supportive of investor's overreaction explanation. Additionally, the stock returns don't necessarily decrease after investment, and the stock returns don't significantly positively correlate with firm profitability or book-to-market, so the result don't support risk-based explanation. Overall, both our portfolio sort and two-stage cross-sectional regression analysis show that behavioral finance theories are better than risk-based theories in explaining the investment anomaly. Evidence from the Chinese stock market provides a useful perspective to understand the debate on the investment anomaly.     

动量和反转投资策略在我国股市中的实证分析

本文采用沪深两市1995年前上市的股票作为样本,发现我国股市中也存在明显的动量和反转盈利,且两种效应的强弱与大盘走势相关,当市场为牛市特征时,动量效应明显强于反转效应;当市场为熊市特征时,则反之.经典的CAPM模型无法解释动量和反转盈利的来源,检验表明投资者对不同类型信息的不同反应方式,可以很好解释我国股市中的动量和反转盈利,利用上述检验结果还可以解释我国股市中许多有趣的特征.     

When Do Opening Stock Returns Tend to be Higher?

Abstract

In this study, I make an effort to formulate a trading rule that would make use of some systematic interday patterns in individual stocks’ opening returns. I analyze intraday price data on all the stocks that were S&P 500 Index constituents during the period from 1993 to 2012. I document that if the general market direction of the previous day's opening session is controlled for, then a stock's opening return tends to be higher if, on the previous trading day, its opening return was relatively high (either positive, or higher than the same day's opening market return) and its open-to-close return was relatively low (either non-positive, or lower than or equal to the same day's open-to-close market return). Finally, for the sampling period, I construct two different investment portfolios involving a long position in the stocks on the days when, according to the findings, their opening returns are expected to be high and a short position in the stocks on the days when, according to the findings, their opening returns are expected to be low. Both portfolios are found to yield significantly positive returns, providing evidence for the practical applicability of the documented patterns in opening stock prices.     

Which drives abnormal returns,over- or under-reaction? Studies applying longitudinal analysis

This article combined both cross-sectional and time-series longitudinal analysis to identify that factor anomalies are driven by either over-reaction or under-reaction. The basic principle is, first, use a factor to form 10 portfolios in the t quarter, then observe the average prices and returns of the 10 portfolios for the previous four quarters and for the following four quarters as well. Samples in this study contain all stocks listed in the US from 1990 to 2010. The empirical evidence shows that the reason for the abnormal returns of value (book-to-price ratios, earnings-to-price ratios, sales-to-price ratios), scale and liquidity factors is over-reaction. Meanwhile, the reason for the abnormal returns of growth factors (return on equity, return on assets and revenue growth rate) is under-reaction. The results provide significant policy implications. The anomaly returns of the value, scale and liquidity factors last longer and are more appropriate to be employed for long-run investment while the growth factors are better suited for short-run investment. Furthermore, a more profitable stock-selection strategy can be formed by simultaneously considering the above two types of factors to capture both of these two sources of anomaly returns.     

中国股票市场风格存在性实证分析

投资风格作为通过投资于特定分割市场或子市场以获得超过正常收益的超额收益的投资决策,对股票市场意义重大。实证研究结果表明：具有相似属性的股票波动相关性较强,中国股票市场风格存在,且可得出：流通市值越小,市净率越大的组合收益率越高。