机构投资者持股与股票收益率波动研究

近几年来,借鉴西方成熟市场的发展经验,我国开始大力发展以投资基金为代表的机构投资者,希望发挥机构投资者的专业能力和信息优势稳定股票市场、降低投资风险。但机构投资者在我国资本市场是否真正起到了应有的作用仍是一个有待商榷的问题。本文以1999年至2007年沪深两市上市公司数据构建面板数据,研究了机构投资者持股比例对股票收益率波动的影响,实证结果证明机构投资者持股比例与股票收益率波动负相关,机构投资者对我国股票市场起到了一定的稳定作用。     

基金网络中机构投资者抱团对股票市场的影响研究

基于Louvain算法从机构投资者网络中提取机构投资者团体,建立以重仓股票为链接的基金网络模型,生成基金团体持股变量,研究机构投资者抱团对股票市场的影响.研究发现:机构投资者抱团行为加剧了公司股价的波动,机构投资者抱团持股比例越大,加剧作用越显著.同时,机构投资者抱团降低了股票的流动性,基金网络交流越密切,抱团持股比例越大,股票流动性成本越高,流动性越差.进一步研究发现,相比牛市,基金在熊市的抱团行为对股价波动的放大效应更明显;在流动性层面,相比牛市,熊市时的机构投资者抱团行为对股票流动性的削弱作用更为显著.     

机构投资者交易行为特征研究

本文通过研究股票收益变化和机构持股变化之间的关系,发现对于高机构持股股票,过去表现较好的股票会吸引机构增加持仓,且机构增持的股票相对减持的股票的后续表现又更好,而低机构持股股票则不然。这表明机构投资者整体上是采用正反馈即惯性交易策略的,而个体投资者的行为则较为随机。对于缺乏投资经验的个体投资者而言,论文结果意味着他们应当委托机构进行理财如投资于基金。     

基于前景理论的中国股市“特质波动率之谜”研究

近年来,关于股市"特质波动率之谜"的研究众多,但尚未有一致的认识。本文运用行为金融学的思想,基于前景理论,从理论和实证两方面研究投资者行为是否对股票特质风险与预期收益的关系产生影响。通过二维分组法和横截面回归法实证发现:我国股市特质风险与预期收益间存在反向关系,并且这种反向关系在股票处于获利域时得到进一步加强,说明股票未实现的资本利得确实影响了特质风险与预期收益间的关系。本文结合我国股市发展现状合理解释了实证结果,有利于进一步深化对投资者行为的重要性的认识。     

我国股票市场交易成本影响因素研究

本文以深交所所有股票2006年的交易数据为研究样本，实证检验我国股票市场影响股票交易成本的主要因素。研究表明，我国股票市场的交易成本高于全球平均水平，同时，持股集中度越低、机构持股比例越低、规模越大和系统性风险越高的股票的交易成本越低，说明目前我国股票市场的交易成本主要受到二级市场流通股筹码状况和股票自身规模及风险因素影响，投资者交易决策存在非理性成份，这与我国新兴市场特性有关。其他因素，包括大股东持股比例、市盈率、收益率、盈利能力、现金充裕程度、成长性、是否为成份指数股和行业因素，没有明显影响股票交易成本。     

大股东交易与中国A股市场股价暴涨暴跌风险北大核心

本文以2008-2016年A股上市公司为样本,研究大股东增持或减持股票如何影响股价极端波动现象的发生。结果表明:大股东交易强度提升显著增加了股价暴涨暴跌风险,其影响主要来源于大股东减持而非大股东增持;上市公司的信息透明度越低、管理层持股比例越高、管理层权力越小,则大股东交易对股价极端波动风险的影响越显著;较高比例的机构投资者持股和独立董事设置能够有效加强对上市公司的监督,削弱大股东交易对股价极端波动风险的不利影响。为了进一步规范大股东交易行为、维护股票市场稳定运行,提出以下对策建议:第一,完善规制大股东交易行为的法律法规和监管规则,防范内幕交易,避免大股东集中、大幅、无序减持股票对市场稳定带来冲击;第二,强化上市公司信息披露要求,提高信息透明度;第三,推动上市公司吸引机构投资者持股、提高独立董事比例,优化公司内部制衡和外部监督机制,以实现对大股东行为的有效制衡和约束。     

公司治理、机构投资者与盈余管理

本文选取沪深两市2003至2005年(非金融类)上市公司的数据,采用最小二乘法和二阶段回归方法,对公司治理、机构投资者与盈余管理三者的关系进行了实证研究。研究发现:机构投资者在一定程度上参与了上市公司的治理,其持股比例与公司治理水平呈正相关关系,说明机构投资者的持股比例越高越有助于提高公司治理水平;公司治理水平与盈余管理程度呈负相关关系;机构投资者的持股比例与盈余管理程度呈负相关关系,说明机构投资者能有效地抑制管理层的盈余管理行为。     

情绪周期与股票收益——基于中国股票市场月相效应的检验

本文采用月相变化这一外生变量衡量投资者情绪的周期性波动，使研究避开了复杂的社会影响过程而专注于外生性的影响。研究发现，股票收益的运行轨迹与投资者情绪周期性波动的轨迹相同，即股票收益会随着投资者情绪的周期性波动而呈现出同样频率的循环性波动。这一现象无论在机构投资者重仓还是中小投资者重仓的股票中均存在，而机构投资者持股比例的增加可以减弱投资者情绪周期波动对决策行为的影响。股市周期作为一种经济环境的刺激变量，在牛、熊市下对投资者机体变量的作用不同，导致其反应变量出现不同程度的变化，在牛市阶段，投资者情绪周期波动对股票收益的影响更为强烈。与非周期性行业相比，投资于周期性行业时，决策所涉及的风险和不确定性更大，放大了情绪波动对于决策行为的作用，导致股票收益随投资者情绪周期性波动而循环性波动的现象在周期性行业中更为明显。     

机构投资者持股与股价同步性分析

本文利用中国证券市场所有A股上市公司2005～2007年的面板数据,对股价同步性和代表机构投资者持股的三个变量——机构投资者持股比例、机构投资者持股变化和持股机构投资者数量进行回归统计,检验了机构投资者持股对股价同步性的影响。研究表明,代表机构投资者持股的三个变量都与股票股价同步性显著负相关,其中机构投资者持股变化是影响股价同步性的决定性因素,其他两个变量都是通过该变量发生作用的。这一结果说明机构投资者利用公司特质信息进行的基于信息的交易提高了股价中的信息含量,降低了股价同步性。     

股票资产波动成分分解及特质风险波动效应研究

采用我国股票市场的个股数据,应用波动分解的方法计算并分解出股票资产组合三个层面的波动成分。经过实证检验以及对特质风险波动效应的建模分析,发现股票特质风险是我国股票资产价格非理性波动的主要风险来源,它与资本市场的信息不确定性、投资者行为存在着确实的内在联系。因此,需根据我国股市的特点以及股票特质风险自身的波动规律,强化信息披露机制,建立上市公司强制分红制度,并加强对投资者的信息交流与教育引导。     

Institutional Investor Trading in a Short Investment Horizon: Evidence from the Korean Stock Market

We examine the weekly trading activities of institutional investors in the Korean stock market. First, we find that average net trades by institutional investors this week are negatively related to one-week lagged returns, suggesting that they could be contrarian traders. Second, our finding shows that institutional investors’ net trades this week are positively related to the net trades next week, consistent with persistent trading and/or herding behavior. Third, we find that institutional net trades are positively related to the post one-week returns. Finally, our findings are most pronounced in the group of short-term institutional investors.     

Institutional investors and stock returns volatility: Empirical evidence from a natural experiment

In this paper, we provide empirical evidence on the impact of institutional investors on stock market returns dynamics. The Polish pension system reform in 1999 and the associated increase in institutional ownership due to the investment activities of pension funds are used as a unique institutional characteristic. Performing a Markov-switching-GARCH analysis we find empirical evidence that the increase of institutional ownership has temporarily changed the volatility structure of aggregate stock returns. The results are interpretable in favor of a stabilizing effect on index stock returns induced by institutional investors.     

Do institutional investors destabilize stock prices? evidence from an emerging market

In this paper, we provide empirical evidence on the impact of institutional investors on stock market returns dynamics in Poland. The Polish pension system reform in 1999 and the associated increase in institutional ownership due to the investment activities of pension funds are used as a unique institutional characteristic. We find robust empirical evidence that the increase of institutional ownership has changed the autocorrelation and volatility structure of aggregate stock returns. However, the findings do not support the hypothesis that institutional investors have destabilized stock prices. The results are interpretable in favor of a stabilizing effect on index stock returns induced by institutional trading.     

Market Segmentation and Cross‐predictability of Returns

We present evidence supporting the hypothesis that due to investor specialization and market segmentation, value‐relevant information diffuses gradually in financial markets. Using the stock market as our setting, we find that (i) stocks that are in economically related supplier and customer industries cross‐predict each other's returns, (ii) the magnitude of return cross‐predictability declines with the number of informed investors in the market as proxied by the level of analyst coverage and institutional ownership, and (iii) changes in the stock holdings of institutional investors mirror the model trading behavior of informed investors.     

Foreign and Local Institutional Ownership and the Speed of Price Adjustment

Abstract:  This paper examines the relation between the speed of price adjustment and stock ownership by foreign and local institutional investors using data from the Korean stock market. We show that returns of stocks with high foreign institutional ownership lead returns of stocks with low foreign institutional ownership, especially after foreign ownership restriction is lifted. Likewise, returns of stocks with high local institutional ownership lead returns of stocks with low local institutional ownership. These results support the idea that foreign institutional (local institutional) investors have faster access to or processing power of new information than local institutional (local individual) investors.     

Futures Market Sentiment and Institutional Investor Behavior in the Spot Market: The Emerging Market in Taiwan

This paper investigates whether and how futures market sentiment and stock market returns heterogeneously affect the trading activities of institutional investors in the spot market in Taiwan. Our empirical results suggest that foreign investors are net sellers whenever futures market sentiment is bullish and net buyers when investor sentiment is bearish. The two types of domestic institutional investors have poor sentiment timing abilities and the price-pressure effect may account for the behavioral differences among institutional investors. In addition, all three institutional investors are momentum traders. Nevertheless, the momentum trading of foreigners is consistent with an information-based model and that of two local institutional investors, as behavior-based models suggest. This indicates that the same trading momentum strategy can lead to different outcomes for different investors, and both information- and behavior-based momentum trading can exist contemporaneously in the Taiwanese stock market.     

US and Domestic Market Gains and Asian Investors’ Overconfident Trading Behavior

We find that subsequent to both US and domestic market gains, both Asian individual and institutional investors increase their trading and that this effect is more pronounced in bull markets, in periods of relatively favorable investor sentiment, in periods of extremely high market returns, and in markets with short‐sale constraints. We also find that individual investors trade more in response to market gains than institutional investors. Moreover, we find that further integration of Asian stock markets with US stock markets after the Asian financial crisis in 1998 is an important reason for Asian investors’ response to US market gains.     

Institutional stock trading on loan market information

One of the most important developments in the corporate loan market over the past decade has been the growing participation of institutional investors. As lenders, institutional investors routinely receive private information about borrowers. However, most of these investors also trade in public securities. This leads to a controversial question: Do institutional investors use private information acquired in the loan market to trade in public securities? This paper examines the stock trading of institutional investors whose portfolios also hold loans. Using the Securities and Exchange Commission filings of loan amendments, we identify institutional investors with access to private information disclosed during loan amendments. We then look at abnormal returns on subsequent stock trades. We find that institutional participants in loan renegotiations subsequently trade in the stock of the same company and outperform trades by other managers and trades in other stocks by approximately 5.4% in annualized terms.     

Did institutions herd during the internet bubble?

We examine the trading behavior of institutional investors during the internet bubble and crash of 1998–2001, and its impact on stock prices. Similar to some recent findings concerning the trading behavior of hedge funds and NASDAQ 100 stocks, we find that during the bubble all types of institutions herded with great intensity into internet stocks for a comprehensive sample of institutional investors and internet stocks. In addition to this, we present three entirely new results. First, institutional herding was much greater than what can be explained by momentum trading. Second, institutions as a group continued to increase their holdings of internet stocks for two quarters past the market peak during the first quarter of 2000, and three quarters past the peak for individual stock prices, suggesting that institutions were unable to time the price peaks. Finally and most importantly, we find positive abnormal returns contemporaneous with institutional herding and negative abnormal returns (reversals) at the point that herding ceased. This finding suggests that institutions’ trading created temporary price pressures, and may have contributed to the bubble.     

Who exacerbates the extreme swings in the Chinese stock market?

We investigate which investors buy or sell relatively more on the days when the absolute value of market returns or the daily range of market index prices exceeds 5% in the Chinese stock market. Unlike Dennis and Strickland [Journal of Finance 57(5): 1923–1949 (2002)] who find that institutional investors are buying (selling) more when there is a large market increase (decline) in U.S. equity markets, we find that institutional investors in China are systematically buying more than the less sophisticated individual investors during extreme market swings, particularly on extreme market-down days. We reveal that institutional investors in China (primarily pension funds), provide a stabilizing influence during market downturn days. Our findings highlight the benefits of having active institutional investors in an extremely volatile emerging market dominated by less sophisticated individual investors.