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.     

基金"搅动"股票收益

基金持股情况变化对股票收益率的波动有当期的推动作用,但基金倾向长期持有选定的股票,并选择持有长期收益率波动较小的股票。同时,我国基金的＂羊群行为＂存在但并不严重,且在一定程度上减少了股价波动,这说明基金管理者已更加理性,并初步形成长期价值投资理念。     

QFII是A股市场的稳定器吗?

对QFII是否是A股市场的稳定器目前并无统一的结论。以沪深300、中证500、蓝筹股和QFII重仓股为样本,实证研究了QFII持股对股价波动的影响。研究发现QFII持股比例对股票价格波动的影响因股票市值大小表现出差异性。首先,以沪深300成分股、蓝筹股为样本进行实证研究时,QFII持股比例对股价波动的影响显著为负;其次,以中证500成分股为样本进行实证研究时,QFII持股比例对股价波动的影响为正,但参数并不显著;再次,以QFII重仓的股票为样本进行实证研究时,发现QFII持股比例对股票价格的波动影响不显著。综合来看,QFII持股并不是股价稳定的充分条件,在股票投资中为尽量规避股价波动风险,除需要关注QFII持股比例外,还需关注股票的市值大小以及QFII在该股票上的投资策略等因素。     

基金经理更换、股票联动与股票价格

基金经理更换打破了基金共同持股投资组合中股票的关联性,降低了股票收益率相关性,进而影响了股票价格。本文基于基金共同持股和基金经理更换构建了对冲投资组合,获得0.1%的日超额收益率。基金投资组合中股票收益率相关性能够解释这种超额收益率,本文发现基金更换经理后,新基金经理重建投资组合,打破了原投资组合中股票间的关联,股票收益率相关性减弱,基金共同持股程度高的股票价格受到了更大影响。基金的被动流动性冲击不能解释本文的发现。本文的研究表明基金经理变更等基金管理行为通过股票收益率相关性对股票价格产生了重要影响。     

投资者关注、股市表现与套利策略——来自百度搜索量的经验证据

本文采用百度指数作为衡量投资者关注度的代理变量,以股票收益率、成交量和股价波动率来描述股票市场的表现,考察投资者关注对当期和下一期股市表现的影响。实证研究发现投资者关注的增加对当期股票成交量和股价波动率有显著的正向影响,而这种影响在下一期会明显减弱。对收益率而言,投资者关注对其的影响具有反转性和非对称性。此外,通过买入关注度低增长股票、卖出关注度高增长股票构建零投资套利组合,并运用Carhart四因素模型进行分析,发现零投资套利组合能够获得显著的超额收益。     

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。     

基金持股期限对股市波动性影响的实证分析

随着我国基金规模的不断扩大,其市场行为对股市的影响也越来越明显.通过选取2001年到2007年沪深两市A股市场及基金的相关数据,从基金的重仓股投资期限与基金的股票周转率两方面分析得出基金持股期限与股市波动性存在显著的正相关,股市波动是基金的股票周转率变化Granger成因,并对我国基金普遍存在投资短期化的原因进行了分析.     

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。     

险资持股对上市公司股价波动的影响研究 ——基于机构投资者异质性视角

保险机构已经成为资本市场重要的机构投资者,其在整个资本市场中的作用日益受到关注.基于机构投资者异质性的视角,对保险机构和证券投资基金、社保基金以及Q FII等其他机构投资者的持股特征进行对比分析,总结梳理保险机构投资者持股的特征.并运用面板数据模型,从长期持股和持股比例变动两个方面对比分析保险机构持股与证券投资基金持股对股价波动的影响.结果表明:在样本期间内,相对于证券投资基金,保险机构长期持股起到了稳定股市的作用,但保险机构持股比例变动会加剧股市的波动.     

信息不对称、机构持股与价格稳定性

本文考察信息不对称、机构持股以及二者的交互作用是否影响到了股票价格的波动。分析发现：（1）信息透明度的增加对股票收益稳定性有促进效应。（2）机构持股对收益稳定性有负的影响，即机构持股加剧了股票收益的波动。（3）在机构未持股时，信息透明对收益波动的边际影响为负；当机构持股时，信息透明的提高在边际进一步促进了价格的稳定性，这说明在机构持股时，提高信息透明对股价的稳定性作用更大。     

Stock Market Sensitivity to U.K. Firms' Pension Discounting Assumptions

New U.K. pension accounting regulations significantly increase the exposure of the balance sheets of U.K. firms to volatilities in pension fund valuations. We examine whether the abnormal returns of firms that voluntarily used market-based pension discount rates are significantly different from the abnormal returns of industry-matched pair samples of firms that retained traditional cost-based valuation assumptions during the period surrounding the release of the related exposure draft. We also examine the interest rate sensitivity of stock price returns over the 4-year period before and after the announcement date. Consistent with our hypotheses, U.K. stock price returns incorporate the effect of unexpected interest rate changes on sources of pension earnings for firms that voluntarily switched to market-based assumptions but do not incorporate these effects for firms that did not switch. These results suggest that unexpected changes in interest rates have a differential effect on a firm's sources of pension, financial, and core earnings.     

A unique view of hedge fund derivatives usage: Safeguard or speculation?

We study the common equity and equity option positions of hedge fund investment advisors over the 1999–2006 period. We find that hedge funds' stock positions predict future returns and that option positions predict both volatility and returns on the underlying stock. A quarterly tracking portfolio of stocks based on publicly observable hedge fund option holdings earns abnormal returns of 1.55% through the end of the quarter. Net of fees, hedge funds using options deliver higher benchmark-adjusted portfolio returns and lower risk than nonusers. The results suggest that hedge fund positions reflect significant timing and selectivity skill.     

人民币汇率波动与中国股票价格报酬之间的相关性——基于2005年至2007年的实证分析

本文以2005年7月21日至2007年9月18日的中国股价与人民币兑美元的名义汇率数据,利用GARCH模型来探讨在这段时间内人民币汇率波动对中国股票价格报酬的影响。实证结果得知,在这段时间内人民币兑美元名义汇率波动是负向影响中国股票价格报酬的,也符合有价证券余额理论的主张;汇率市场对股票市场的影响在宏观决策中应予以高度重视。     

Spillover and Cojumps Between the U.S. and Chinese Stock Markets

There is an urgent need to understand the spillover and cojump effects between the U.S. and Chinese stock markets. The paper finds that since July 2005, the U.S. stock market has caused short-run spillover effects on returns on the Chinese stock market. More specifically, price changes in the United States can be used to predict both closing-to-opening and closing-to-closing returns on the Chinese stock market on the next day. However, there is no significant volatility spillover between the two markets. Both markets have shown stronger cojump behavior since the subprime crisis. The return relationships between the two stock markets are robust.     

The Value and Risk of Defined Contribution Pension Schemes: International Evidence

We use historical data on investment returns and labor income from 16 countries to quantify the value and risk of defined contribution pension plans, building frequency distributions of pension fund and pension replacement ratios for each country. We show that pension risk is substantial and find that pension fund ratios are lower and less variable than when the correlation between wage growth and investment returns is ignored, typically halving the median pension fund ratio. We also show that an all‐equity fund is the dominant investment strategy across all countries, although sometimes a life‐cycle strategy insures against downside risk.     

Investor Sentiment and Stock Returns: Evidence from Turkey

This paper investigates the relation between investor sentiment and stock returns on the Istanbul Stock Exchange, employing vector autoregressive (VAR) analysis and Granger causality tests. The sample period extends from July 1997 to June 2005. In the VAR models, stock portfolio returns and investor sentiment proxies are used as endogenous variables. Two dummy variables accounting for natural and economic crises are used as exogenous variables. The analysis results suggest that, excepting shares of equity issues in aggregate issues, stock portfolio returns seem to affect all investor sentiment proxies, namely closed-end fund discount, mutual fund flows, odd-lot sales-to-purchases ratio, and repo holdings of mutual funds. Investor sentiment does not appear to forecast future stock returns; only the turnover ratio of the stock market seems to have forecasting potential.     

Free Cash Flow,Issuance Costs,and Stock Prices

We develop a dynamic model of a firm facing agency costs of free cash flow and external financing costs, and derive an explicit solution for the firm's optimal balance sheet dynamics. Financial frictions affect issuance and dividend policies, the value of cash holdings, and the dynamics of stock prices. The model predicts that the marginal value of cash varies negatively with the stock price, and positively with the volatility of the stock price. This yields novel insights on the asymmetric volatility phenomenon, on risk management policies, and on how business cycles and agency costs affect the volatility of stock returns.     

Announcement Effects and Asymmetric Volatility in Industry Stock Returns: Evidence from Taiwan

This study employs financial econometric models to examine the asymmetric volatility of equity returns in response to monetary policy announcements in the Taiwanese stock market. The meetings of the board of directors at the Central Bank of the Republic of China (Taiwan) are considered for testing the announcement effects. The asymmetric generalized autoregressive conditional heteroskedasticity (GARCH) model and the smooth transition autoregression with GARCH model are used to measure equity returns' asymmetric volatility. We conclude that the asymmetric volatility of countercyclical equity returns can be identified. Our findings support the leverage effect of stock price changes for most industry equity returns in Taiwan.