Stock price synchronicity to oil shocks across quantiles: Evidence from Chinese oil firms

This paper investigates behaviour of stock price synchronicity to oil shocks across quantiles for Chinese oil firms. The spillover effects of the oil market on a firm are segregated into firm-specific and market-wide information. First, our results report a higher level of synchronicity by dynamic conditional correlations than by R-square since the former better captures dynamic linear dependence. Second, we find strong evidence of size effect. In particular, stock price synchronicity is generally higher in large-cap firms than in small-cap ones. Oil shocks affect synchronicity in the upper quantiles differently based on firm size. Third, we also find that synchronicity responds to oil shocks significantly in extreme low quantiles, implying that shocks in the oil market are transmitted to Chinese oil firms via firm-specific information. Finally, we determine that oil shocks have little or no immediate impact on stock price synchronicity; instead, cumulative lagged effect is evident. This evidence highlights the lagging effect of spillover of oil shocks on Chinese oil firms.     

Analyst coverage and stock return synchronicity: evidence from regulation changes in China’s IPO market

This article investigates the relation between analyst coverage and stock return synchronicity in the IPO market. Using a unique data set in China from 2005 to 2012, we find a significantly different effect of analyst coverage on synchronicity before and after the implementation of important 2009 IPO regulation changes in China. Specifically, we document that analyst coverage reduces synchronicity but that this effect is significant only after 2009. In addition, we extend this research to further distinguish the information production role of underwriter and independent analysts. We find that prior to 2009, underwriter analysts’ coverage decreases synchronicity but independent analysts’ coverage does not. However, in the post-2009 period, both types of analyst coverage are significantly and inversely associated with synchronicity. Overall, our results support analysts’ role as producers of firm-specific information in an emerging IPO market and shows that this role depends on the institutional environment.     

终极控股股东的盈余管理影响股价同步性的实证研究

以2008—2012年中国沪深两市A股上市公司为研究样本,通过回归分析研究了在中国资本市场发展不完善、股权集中的条件下终极控股股东的盈余管理对公司股价同步性的影响。研究结果表明:终极控股股东有强烈动机影响公司的盈余信息披露,导致噪音信息增多、公司的股价同步性下降,股价同步性更多体现市场噪音量而非信息效率;非国有控股的上市公司通过操纵盈余来影响股价进而影响股价同步性的能力强于国有控股的上市公司。     

机构投资者、现金股利政策与股票市场稳定性研究——来自2005—2009年中国A股上市公司的经验证据

论文基于2005—2009年中国A股上市公司年报数据的实证研究发现,当投资于发放现金股利的公司股票时,机构投资者持股比例与上市公司股票换手率、股票收益波动率、股价同步性等反映和衡量股票市场稳定性的三个渐次递进维度的指标都显著负相关;而当投资于不发放现金股利的公司股票时,机构投资者持股比例与衡量股票市场稳定性的指标显著正相关抑或不具有显著影响关系。这些结果表明上市公司的现金股利政策直接影响着机构投资者是选择长期的价值投资行为还是进行短期频繁的投机炒作,进而影响机构投资者稳定股票市场功能的有效发挥。论文的研究结论对于股票全流通时代发展机构投资者、引导投资者的长期价值投资行为以促进中国资本市场的健康稳定发展具有重要的启示和政策意义。     

Asset pricing and institutional investors with disagreements

We develop a dynamic asset pricing model with two institutional investors who have benchmark incentives and who disagree about the underlying economy. We derive semi-closed form expressions for all equilibrium quantities. We find that the benchmark stock price increases and the non-benchmark stock price decreases with the benchmark incentives. Furthermore, each stock price decreases with its own disagreement and increases with the other stock disagreement. We also show that there is a positive relationship between the co-movement of the stocks and the benchmark incentives, but that this co-movement is negative with the disagreements, owing to the endogenous risk-sharing mechanisms. Moreover, we find that, when one stock disagreement increases, the optimistic institutional investor always takes positions on this stock by shorting the other stock and the bond in order to hedge against the risk of market changes, in line with the pessimistic investor's beliefs.     

股价同步性与信息效率

本文通过考察股价同步性与信息效率之间的关系,澄清一个近来在金融学术和实务上有些模糊的观点,即经典的CAPM模型所决定的股价同步性,是否意味着企业信息披露更有效？通过比较信息披露指标与同步性测度的回归结果以及进一步根据同步性构造一系列组合收益发现,较低的股价同步性并不意味着更高的信息效率。事实上,较高和较低的股价同步性都意味着比较差的信息披露效率,二者呈现出“倒U”型关系。这为今后的学术研究和实务分析提供了一个新的基础。     

中国上市公司透明度与股价波动同步性的实证分析

本文以我国上市公司2001至2004年的面板数据为研究样本，从会计信息系统和组织结构复杂性两个维度，建立了一套客观反映我国上市公司综合透明度水平的评价指标体系，并在此基础上，考察公司透明度对股价波动同步性的影响。实证结果表明，公司的会计信息透明度和组织结构透明度越低，股票价格所反映出的公司特质信息的含量越低，股价波动的同步性越强。这一研究结果不仅支持了股价波动的信息含量差异源于公司透明度差异的论点，而且拓展了有关公司透明度的研究，对更加深入且全面地理解公司透明度的经济后果有着重要的启示作用。     

股票网络平台中的噪音会影响股价同步性吗

股价同步性是衡量资本市场信息效率的重要指标。股价同步性的影响机制一直以来都是金融研究的热点问题。本文使用文本分析的方法,通过机器学习度量了东方财富股吧中股民发帖评论中的非理性噪音,检验了股票网络平台中的噪音与股价同步性之间的关系。研究发现：第一,股票网络平台中的噪音会促使投资者做出非理性的投资决策,进而降低股价变动的同步性。噪音评论占全部评论的比例越高,上市公司的股价同步性越低,而且两者之间呈现倒U型的非线性关系。第二,公司个股新闻与公告数量的增加、分析师关注度的提高与外部审计质量的提升,均可以减弱股票网络平台中的噪音对股价同步性的影响。本文关注网络新媒体中的噪音对股价同步性的影响,研究结论对于监管部门加强网络信息监测以及上市公司进一步完善信息披露渠道具有现实意义。     

信息传递模式、投资者心理偏差与股价“同涨同跌”现象

股价"同涨同跌"又称"股价同步性",是世界各国证券市场发展过程中的一种普遍现象,也是近年来财务学的研究热点和前沿课题。本文收集1994—2004年中国股市的相关数据,用R2度量股价同步性,对股票收益的"惯性"和"反转"与R2之间的关系进行系统的实证检验和理论分析。研究发现:(1)总体上,我国股市不存在"惯性"现象,而存在显著"反转"现象,并且反转效应随着R2的上升而逐渐减弱,两者呈负相关关系;(2)不同市场态势下惯性和反转的表现形式不同,且与R2的关系也不同:牛市阶段存在"反转"现象,且R2越高反转越明显;在熊市阶段存在"惯性"现象,且R2越小惯性越明显,说明不同市场态势下股价同步性的生成机理不同。对此,作者提出了一种基于信息与心理行为互动关系的新解释,丰富并完善了股价同步性形成机理的理论研究。     

境外大股东持股与股价同步性研究

以2006-2010年的中国所有上市公司为研究对象,采用多种方法分析境外大股东与股价同步性的关系。结果发现：首先,境外大股东在来源地方面具有显著的地缘特征和经贸关系特征;其次,行业不同股价同步性呈现出较大差异,如采掘业、金融业的股价同步性很高,而制造业、批发零售业相对较小;再次,境外大股东持股与股价同步性呈显著负相关性;最后,来自非港澳台的直接境外大股东对股价同步性有更大的影响,而直接境外大股东是否为金融机构差异不明显。     

Market Underreaction and Overreaction of Technology Stocks

Several studies have assessed stock market under- or overreaction of stocks and there is some agreement among them. However, there is much disagreement about what constitutes market underreaction or overreaction, and the conditions that cause it. The substantial variation in results among studies may be partially attributed to the types of firms that are contained in any sample. We investigate this premise by focusing on a sample of technology stocks that experienced an extreme change in stock price, along with a corresponding control sample of non-technology stocks that experienced a similar extreme change in stock price on the same day.

Based on the subsequent stock price behavior of each sample, we find a greater degree of overreaction within extreme positive changes in technology stock prices (winners) than in non-technology stock prices. In addition, we find a greater degree of underreaction within extreme negative changes in technology stock prices (losers) than in non-technology stock prices. When considering winners and losers collectively for technology and non-technology firms, it appears the market is overoptimistic when it initially revalues technology stock prices relative to non-technology stock prices.

The degree of under- or overreaction of technology stocks varies within the sample of technology stocks, and is conditioned on firm-specific characteristics. Overall, our results suggest that technology stocks exhibit unique stock price behavior subsequent to an extreme change in price, and that this unique behavior can even vary among technology firms according to firm-specific characteristics.     

客户股价崩盘风险对供应商具有传染效应吗?

文章利用手工整理的2007?2013年800对客户与供应商均为上市公司的供应链公司数据,探讨了客户股价崩盘风险是否会通过密切的供应链关系传染给供应商.研究发现:(1)客户股价崩盘风险对供应商具有传染效应,且这一传染效应主要出现在供应商自身抗风险能力不足时.(2)客户与供应商的关系越重要、越专有、越稳定、越良性,客户股价崩盘风险对供应商的传染效应越强.这表明由于密切的经济联系,当客户股价崩盘风险较高时,供应商可能会受牵连而发生崩盘.文章的研究为传染文献提供了新的适用情形,也展示了客户影响供应商的独特路径,从而丰富了传染效应和客户供应商关系的相关文献.     

Influence of economic factors on the valuation effects of debt offerings

The obejective of this paper is to determine whether the share price responses to debt offerings are influenced cross-sectially by economic factors. We develop hypotheses that share price responses are inversely related to nominal interest rates, and to the issuing firm's stock price level relative to the market, and positively related to economic growth. After controlling for firm-specific characteristics used in previous studies, we find that the share price responses to straight debt offerings are not significantly related to the nominal interest rates or to the issuing firm's relative stock price level, but are positively related to the economic growth. We also find that share price responses to convertible debt offerings are significantly related to the nominal interest rates, the issuing firm's relative stock price level, and economic growth in the manner hypothesized. These results imply that the signal emitted by a firm's debt offering can be influecnced not only by firm-specific characteristics, but also by prevailing economic conditions.     

限售股流通与股价效应关系的实证研究

本文运用事件研究法对限售股上市流通的股价效应进行了实证研究。研究结果袁明：限售股的上市流通带来负的股价效应;样本公司的特征及股票的交易特性显著影响股价效应;在累积超额收益率为正的样本中,累积超额收益率与净资产收益率负相关,与区间日均股票换手率、股票每股收益正相关;在累积超额收益率为负的样本中,累积超额收益率与IPO到限售流通股上市流通的时间、账面市值比、区间日均成交量负相关。     

How does the diversity of investors’ beliefs affect stock price informativeness?

A growing number of studies have investigated the role of stock prices in aggregating private information and guiding resource reallocation. However, this article may be the first attempt to study how the diversity of beliefs affects stock price informativeness. The framework of the noisy rational expectations model shows that stock informativeness is determined by both the precision and use of private information in trading. If private beliefs about the value are highly diverse, the aggregate average opinion revealed in a stock’s price will be more accurate and, thus, more informative. As the price becomes more informative, however, individual investors will rely less on their private information. When this occurs, less private information will be absorbed in price, which, in turn, reduces price informativeness. Our model shows that the relationship between belief diversity and price informativeness is U-shaped in equilibrium.     

政府审计的外部治理效应:基于股价崩盘风险的研究

作为一项强有力的政府监管措施,政府审计的作用及有效性是一个重要的研究话题.文章利用2009-2015年审计署实施的中央企业审计事件,从公司股价崩盘风险角度,采用双重差分模型研究了政府审计的外部治理效应.研究发现,在政府审计实施后,被审计公司的股价崩盘风险显著下降.在一系列稳健性检验之后,上述结果依然存在.进一步研究表明,政府审计通过促使被审计公司及时披露负面信息,缓解了公司股价崩盘风险;此外,政府审计越频繁,其缓解股价崩盘风险的作用越强,而且政府审计还存在溢出效应,未被审计中央企业在审计事件发生后的股价崩盘风险也出现下降.文章对于评估和完善中国政府监管具有重要的理论与实践意义.     

融券约束和市场定价效率*——基于我国股票市场转融通的准自然实验证据

本文从融券约束的视角出发，研究我国股票市场融券机制对标的股票价格发现效率的影响。相比于融券交易量，融券约束可以更好地识别融券机制的作用。因为它可以从交易渠道、信息渠道、外部监管渠道对股价产生影响。笔者利用转融通的实施作为准自然实验，识别出了融券约束放松后标的股票价格发现效率的变化。实证结果显示融券约束放松后：（1）在市场下跌的情况下股价的共同趋势增强，意味着此时股价中包含的个股特质性信息含量降低，而市场上涨时则不存在这种效应；（2）股价对市场信息的反应速度增快；（3）股价更加接近随机游走，即股价的可预测性降低。本文的政策启示是，适当降低融券约束、扩大机构投资者比例、保持较高的融券交易准入门槛以及加强投资者教育可以促进融券机制发挥积极作用。     

Informed trade,uninformed trade and stock price delay

The probability of informed trading (PIN), a measure of information-based trading risk, has been broadly applied to empirical studies on asset pricing. However, it is still controversial whether PIN measures exclusively the risk of firm-specific private information or it also captures the private interpretation of market wide public information. This article examines the relevance of PIN to the delayed response of stock prices to market-wide information. We find that PIN significantly explains individual stock price delay even controlling for size, liquidity and risk, and low-PIN stock prices adjust to market information more rapidly not only because of a notably high level of informed trading but also an even much higher level of uninformed trading. Our findings support the notion that PIN also captures the private skilled interpretation of public common factor information by sophisticated investors, and provide new empirical evidence on how information-based trading affects the speed at which stock prices adjust to information.     

国有机构投资者持股能提升企业投资效率吗?

具有国资背景的机构投资者,对于资本市场平稳发展具有重要意义。本文基于我国2015—2019年A股上市公司样本,考察持股对企业投资效率的影响。研究发现,持股显著提升了企业投资效率,并且该影响在代理冲突更严重和所处信息环境更不透明的公司中更加显著。机制检验表明,降低企业内外部信息不对称和代理成本是持股提升企业投资效率的重要渠道。进一步研究发现,国有机构投资者持股时间越长,对企业非效率投资的治理效果越好;细分国有机构投资者类型后发现,致力于长期维护资本市场稳定和上市公司长期健康发展的证金公司和汇金公司对企业投资效率的提升作用显著,但没有发现“救市”基金和外管局旗下的投资平台对企业投资效率有提升作用。研究结论从企业投资效率视角为国有机构投资者持股在微观企业日常经营中发挥的治理作用提供了新颖的经验证据,对进一步提高我国上市公司质量具有启示意义。     

分析师利益冲突、乐观偏差与股价崩盘风险

"股价崩盘风险"是当前金融危机背景下财务学的一个研究热点。本文使用2003-2010年中国A股上市公司的数据,研究分析师乐观偏差是否影响上市公司股价崩盘风险,并考察分析师面临的"利益冲突"是否会加剧乐观偏差对股价崩盘风险的影响。研究发现:(1)分析师乐观偏差与上市公司未来股价崩盘风险之间显著正相关,且此关系在"牛市"更为显著;(2)机构投资者持股比例越高,机构投资者数量越多,公司存在再融资行为,以及来自前五大佣金收入券商的分析师比例越高,分析师乐观偏差与崩盘风险之间的正向关系就更为显著,说明"利益冲突"会加剧两者的关系。本文的研究对于全面认识分析师在资本市场中的作用,以及如何降低我国股价崩盘风险、促进股市平稳发展具有重要的理论和现实意义。