中国货币政策与股票横截面收益研究

本文基于沪深股市1993～2008年剔除了金融类股的所有A股数据,研究了中国证券市场上货币政策与股票横截面收益之间的关系。本文发现,在货币紧缩情况下,股票的Beta值与股票收益是成正比例关系的,而在货币扩张情况下,这种正比关系的程度减小,股票的Beta越大,其收益反而减小;在货币紧缩情况下,股票的市值规模与股票收益是成反比例关系的,而在货币扩张情况下,这种反比关系的程度变大,股票的市值规模越小,其收益增加的程度更大;在货币紧缩情况下,股票的账面市值比与股票收益是成正比例关系的,而在货币扩张情况下,这种正比关系的程度变大,股票的账面市值比越大,其收益增加的程度也越大。     

基于中国股市的动量策略和反转策略盈利性研究

本文测试了中国股票市场中A股的反转策略和动量策略的盈利性,实证结果证明了短期内的动量收益,而反转收益存在于中长期和长期。在对两类收益的原因探析中,本文证明反转收益部分归因于规模效应。Beta因素对两类收益都没有解释力。本文同时还测试了Fama-French三因素模型,发现包含市场风险、规模差异和账面市场价值比在内的三类公共因素均不能有效解释反转收益和动量收益。     

股票横截面收益特性“异常”与行为金融学

面对股票市场横截面收益特性不符合CAPM，理论界有很多观点，其中最活跃和最有发展前途的就是所谓的行为金融学。行为金融学对传统的理性人假设进行了各种形式的放宽，研究非严格理性的投资的行为将对股票市场的特性带来怎样的影响。     

中国股市个股非流动性、换手率和短期反转的关系

本文在排除买卖报价反弹、周末效应等干扰因素的前提下,利用分组构建逆势投资组合及Fama-Macbeth回归方法,研究周期下我国股市中的短期收益反转现象。实证结果表明：我国股市中存在短期收益反转现象,短期反转在股票输家中表现更为明显;股票收益的短期反转随着非流动性的增强而增强;我国股市具有极高换手率的投资组合表现出特殊性,极高换手率对股票输家的短期收益反转具有抑制作用,而对股票赢家的短期收益反转具有促进作用。     

中国上市公司融资选择的市场时机效应——基于股票换手率和股票收益的实证检验

自从市场时机资本结构理论提出以来，国内外学者从理论的解释能力和实用性等方面对这一新兴融资决策理论进行了大量研究，并得出许多有意义的结论。然而目前的实证检验主要基于市值账面比（M／B）指标作为市场时机代理变量，这一指标引起学者们很大争议，研究结论缺乏可靠性。本文根据我国资本市场实际特征选择股票换手率作为市场时机代理变量，实证检验了市场时机与外部融资方式选择的关系，同时引入股票收益变量检验市场时机对资本结构动态变动的综合影响。研究结论显示，换手率在企业权益融资中具有重要作用，换手率较高时企业选择发行更多的股权融资，股票换手率和股票收益均对资本结构变动具有显著的负向影响。这表明我国上市公司确实存在着融资选择的市场时机效应。     

新闻情绪风险与股票收益

风险与收益的关系一直以来是学术界关注的重点问题,媒体新闻的内容和情绪会改变投资者决策并影响股票市场,因此从新闻情绪的角度分析风险收益的关系是十分有意义的。本文采用新闻文本数据构建了新闻情绪这一指标,并利用滚动回归的方法构建新闻情绪风险指数,基于2005—2020年的中国沪深两市A股上市公司数据对新闻情绪风险和股票收益之间的关系进行研究。研究结果表明,新闻情绪风险较高的公司具有更高的市场风险和波动性,同时这些公司还具有市值较小、上市时间较短的特征;此外,新闻情绪风险较高的投资组合具有较低的超额收益,在公司规模相同的条件下依旧得到了相同的结论。由此可见,中国股票市场存在新闻情绪的低风险定价异象。     

中国股票市场关于股票收益的两个假设的检验

使用方差比方法检验中国股票市场上股票收益服从随机游走的假设，检验结果拒绝了该假设。而使用Geweke和Porter—Hudak(1983)提出的分数差分检验，检验结果却支持股票收益存在长期记忆的假设。长期记忆性的存在使得有可能通过建立非线性经济计量模型以改进价格预测效果。     

上市公司综合盈利水平与股票收益

本文基于2000-2017年上市公司的财务及股票交易数据,研究了上市公司综合盈利水平与股票收益之间的关系。我们使用目前资产定价文献中较新的偏最小二乘法和组合预测法,从12个衡量公司盈利能力的指标中提取了一个测度上市公司综合盈利水平的指标。研究结果显示,上市公司综合盈利水平能够显著预测未来股票收益。使用单因子偏最小二乘法、取12个月斜率的平均值构造的综合盈利水平最有效,以其构建的多空对冲投资组合能产生15%的年平均收益,夏普比率达到0.75。与此对应,组合预测法提取的上市公司综合盈利水平的预测能力稍低,但依然显著。在控制了其他公司特征变量后,综合盈利水平对于股票收益的解释能力依然稳健。本文还从经济机制的角度出发,探讨了综合盈利水平对收益的预测来源。我们发现,上市公司综合盈利水平与股票预期回报的正向关系在投资摩擦更低的组中更高,而在错误定价程度更高的组通常更低。这些结果支持了基于投资摩擦的Q理论,而与行为金融的错误定价理论相悖。     

Individual Investor Trading and Stock Returns

This paper investigates the dynamic relation between net individual investor trading and short‐horizon returns for a large cross‐section of NYSE stocks. The evidence indicates that individuals tend to buy stocks following declines in the previous month and sell following price increases. We document positive excess returns in the month following intense buying by individuals and negative excess returns after individuals sell, which we show is distinct from the previously shown past return or volume effects. The patterns we document are consistent with the notion that risk‐averse individuals provide liquidity to meet institutional demand for immediacy.     

Media Coverage and the Cross-section of Stock Returns

By reaching a broad population of investors, mass media can alleviate informational frictions and affect security pricing even if it does not supply genuine news. We investigate this hypothesis by studying the cross-sectional relation between media coverage and expected stock returns. We find that stocks with no media coverage earn higher returns than stocks with high media coverage even after controlling for well-known risk factors. These results are more pronounced among small stocks and stocks with high individual ownership, low analyst following, and high idiosyncratic volatility. Our findings suggest that the breadth of information dissemination affects stock returns.     

Trading Volume and Cross-Autocorrelations in Stock Returns

This paper finds that trading volume is a significant determinant of the lead-lag patterns observed in stock returns. Daily and weekly returns on high volume portfolios lead returns on low volume portfolios, controlling for firm size. Nonsynchronous trading or low volume portfolio autocorrelations cannot explain these findings. These patterns arise because returns on low volume portfolios respond more slowly to information in market returns. The speed of adjustment of individual stocks confirms these findings. Overall, the results indicate that differential speed of adjustment to information is a significant source of the cross-autocorrelation patterns in short-horizon stock returns.     

Stock Returns in Thinly Traded Markets

We examine the share price behavior of thinly traded NASDAQ National Market System stocks during periods when financial markets are open but the individual stocks do not trade. The absence of trade allows us to isolate the effect of nontrading from that of market closure. We find that nontrading stocks have negative mean returns and lower variances regardless of whether markets are open or closed. Two-day returns that include one nontrading day have a mean daily return of -0.226% compared to +0.164% for two-day returns over consecutive trading days. Two-day returns that include one nontrading day have only 3.8% higher variance than one-day returns. We conclude that the relation between transaction arrival, mean returns, and volatility depends on whether a stock is trading and not simply on whether the market is open.     

A Model of Returns and Trading in Futures Markets

This paper develops an equilibrium model of a competitive futures market in which investors trade to hedge positions and to speculate on their private information. Equilibrium return and trading patterns are examined. (1) In markets where the information asymmetry among investors is small, the return volatility of a futures contract decreases with time-to-maturity (i.e., the Samuelson effect holds). (2) However, in markets where the information asymmetry among investors is large, the Samuelson effect need not hold. (3) Additionally, the model generates rich time-to-maturity patterns in open interest and spot price volatility that are consistent with empirical findings.     

成交量和回报率对信息扰动的市场反应研究——以中国A股市场为例

用BVAR和BMAR模型及脉冲—响应分析方法来考察中国股票市场上成交量和回报率对信息扰动的动态反应情况得出,公共扰动和永久性扰动是回报率的主要决定因素,而非公共扰动和暂时性扰动则是成交量的主要决定因素。但是公共扰动和永久性扰动对成交量有明显影响;非公共扰动和暂时性扰动对回报率有明显影响。     

Informed Trading in Stock and Option Markets

We investigate the contribution of option markets to price discovery, using a modification of Hasbrouck's (1995) "information share" approach. Based on five years of stock and options data for 60 firms, we estimate the option market's contribution to price discovery to be about 17% on average. Option market price discovery is related to trading volume and spreads in both markets, and stock volatility. Price discovery across option strike prices is related to leverage, trading volume, and spreads. Our results are consistent with theoretical arguments that informed investors trade in both stock and option markets, suggesting an important informational role for options.     

Another Look at the Cross-section of Expected Stock Returns

Our examination of the cross-section of expected returns reveals economically and statistically significant compensation (about 6 to 9 percent per annum) for beta risk when betas are estimated from time-series regressions of annual portfolio returns on the annual return on the equally weighted market index. The relation between book-to-market equity and returns is weaker and less consistent than that in Fama and French (1992). We conjecture that past book-to-market results using COMPUS-TAT data are affected by a selection bias and provide indirect evidence.     

投资者分歧、异常交易量和股票横截面收益率预测——基于中国股票市场的经验证据

本文定义月度异常交易量为本月与上个月交易金额的比值,发现中国市场月度收益率与滞后一个月的异常交易量显著负相关。在控制了公司规模、账面市值比、流动性以及动量效应等指标后仍然具有显著的解释作用。进一步研究表明,在出现高异常交易量后的12个月内,换手率和特质性波动率都有大幅上升。本文认为,交易量上升代表着市场分歧程度和受关注程度的增加,在卖空约束下会使得股票价值高估,从而造成未来收益率下降。