短期羊群行为的影响因素与价格效应——基于高频数据的实证检验

通过创新性地使用日内高频交易数据对A股市场中的羊群行为进行研究,本文发现:(1)羊群行为具有短期脆弱性特征,随着度量频率的提高,羊群行为的程度严格递增。(2)信息不对称程度、机构投资者比例、股票规模等因素,会显著影响短期羊群行为程度。(3)短期羊群行为会伴随着明显的价格反转:短期买入(卖出)羊群行为后,股票的超额收益显著为负(正),并且短期羊群行为越显著,价格反转的程度越大。(4)价格反转效应存在不对称性:规模越大、交易越活跃的股票,短期买入羊群行为的价格反转越明显,而短期卖出羊群行为的价格反转越不明显。     

高管减持如何影响投资者预期?——基于超额融券的经验证据

随着我国融资融券业务逐步扩容,投资者向证券公司融券卖出的卖空交易成为市场消化负面信息的重要机制。本文以高管减持事件窗口期的超额融券量为研究对象,采用事件研究法考察我国企业高管减持所任职公司股票对市场预期的影响。实证结果表明,相比估计期,高管减持窗口期超额融券量显著增长,并且减持比例越高或者减持金额越大,超额融券量越高,表明高管减持显著降低了外部投资者对公司股票的价值预期。进一步研究显示,良好的信息透明度能够显著降低高管减持对超额融券量的正向影响。本文用超额融券量直观地度量投资者预期变化,丰富和发展了高管减持经济后果的研究,对规范我国上市公司高管减持行为及监管部门完善相关监管规定具有启示意义。     

企业并购影响高管薪酬业绩敏感性吗?——基于中国国有上市公司的实证分析

本文以中国沪深股市2006-2010年间作为买方发生并购行为的362个国有上市公司为研究对象,分析了公司并购行为对高管薪酬与公司业绩的敏感度的影响。研究发现,公司资产回报率、市场回报率与公司高管薪酬显著正相关。说明并购前,高管薪酬与资产回报率以及市场回报率显著正相关,即高管薪酬与公司业绩敏感度较高。并购所增加的会计业绩和市场业绩与高管薪酬在10%的水平下显著负相关。可见,企业并购显著降低了高管薪酬与公司资产回报率以及市场回报率的业绩敏感度。并购规模无论是通过会计绩效还是市场绩效检验分析,都显著与高管薪酬正相关,说明高管薪酬与并购规模的扩大显著正相关。为进一步分析并购绩效是否会影响高管薪酬变动,本文采用差分模型分析了高管薪酬变化值与并购业绩变化值和并购规模变化的关系,研究发现,高管薪酬的变化与并购绩效无显著的相关关系,而与并购增加的公司规模显著正相关。     

资本市场开放与高管在职消费——基于沪深港通交易制度的准自然实验

资本市场变革如何促进上市公司高质量发展是当前金融改革所面临的重大课题.作为资本市场对外开放的重要制度创新,沪深港通交易制度引起学界广泛关注.本文以高管在职消费为切入点,利用沪深港通这一外生政策研究了资本市场开放对标的公司高管在职消费的影响及其机理.研究发现,沪深港通交易制度实施显著降低了标的公司高管在职消费水平.机制检验表明资本市场开放通过改善信息环境、提高货币薪酬激励效果以及促进股利支付等途径抑制高管在职消费.沪深港通交易制度对高管在职消费的外部治理效应亦存在持续性.本文不仅丰富了资本市场开放经济后果的研究文献,也拓展了在职消费影响因素的研究视角,亦为沪深港通交易制度的不断完善提供了有益借鉴.     

高管股权激励与银行信贷决策——基于我国民营上市公司的经验证据

本文实证考察我国民营上市公司高管股权激励对银行信贷决策的影响。研究发现,高管股权激励强度越高,公司获得的银行借款越多,但主要体现在短期借款增加,而长期借款没有显著增加。进一步研究发现,相比实施经营持股激励的公司,实施股票期权或限制性股票激励的公司获得显著更多的银行借款尤其是短期借款,而长期借款在两类公司不存在显著差异;相比激励型股权激励公司,福利型股权激励公司获得显著更多的短期借款。研究证实,高管激励机制的完善有助于民营企业获得更多银行借款,缓解"信贷歧视",但面对股权激励的风险承担效应与福利效应,银行会通过调整贷款期限来降低自身的信贷风险。     

企业社会责任:“真心”抑或“幌子”?——基于高管内幕交易视角的研究

企业承担社会责任究竟是“真心”还是“幌子”?与现有研究聚焦于考察社会责任对企业行为的影响不同,本文基于高管个体行为视角,实证检验企业社会责任对高管个体证券交易行为的影响。基于2008～2014年中国沪深A股上市公司高管10338个内幕交易样本的实证结果显示:(1)企业承担社会责任不仅能抑制高管内幕交易的规模,更能显著降低高管内幕交易获利性,这表明作为社会责任的谋划者,企业高管并未以社会责任为“幌子”牟取个人证券交易的私利,在一定程度上提供了企业“真心”承担社会责任的证据;(2)进一步从“信息模型”和“声誉模型”双重视角探究发现,在企业信息不透明和高管个人声誉较差的情况下,企业社会责任对高管内幕交易获利性的抑制作用更为显著;并且相较于高管个人声誉较差的情况,企业社会责任在信息不透明的情况下对高管内幕交易获利性的抑制作用更强。总之,本研究从高管个体行为视角提供了企业社会责任具有积极治理作用的证据,不仅丰富了企业承担社会责任经济后果的研究,同时,对利益相关者也具有实践指导意义。     

企业社会责任:“真心”抑或“幌子”?——基于高管内幕交易视角的研究

企业承担社会责任究竟是“真心”还是“幌子”?与现有研究聚焦于考察社会责任对企业行为的影响不同,本文基于高管个体行为视角,实证检验企业社会责任对高管个体证券交易行为的影响。基于2008～2014年中国沪深A股上市公司高管10338个内幕交易样本的实证结果显示:(1)企业承担社会责任不仅能抑制高管内幕交易的规模,更能显著降低高管内幕交易获利性,这表明作为社会责任的谋划者,企业高管并未以社会责任为“幌子”牟取个人证券交易的私利,在一定程度上提供了企业“真心”承担社会责任的证据;(2)进一步从“信息模型”和“声誉模型”双重视角探究发现,在企业信息不透明和高管个人声誉较差的情况下,企业社会责任对高管内幕交易获利性的抑制作用更为显著;并且相较于高管个人声誉较差的情况,企业社会责任在信息不透明的情况下对高管内幕交易获利性的抑制作用更强。总之,本研究从高管个体行为视角提供了企业社会责任具有积极治理作用的证据,不仅丰富了企业承担社会责任经济后果的研究,同时,对利益相关者也具有实践指导意义。     

高管增持春江水暖鸭先知？

高管增持事件综述高管增持事件是指公司高管在二级市场买入本公司股票的一种投资行为。从逻辑上分析，高管增持行为可以反映出管理层对于本公司股票价格及公司未来发展状况的态度，大量的买入行为可能表示管理层认为目前公司价值被低估、未来价值提升空间较大，或者对于公司未来经营充满信心，     

大宗交易对股价波动的羊群效应研究

以2018-2020年沪深A股发生大宗交易的上市公司为样本,实证检验了上市公司大宗交易定价对其二级市场股票价格波动的影响机理。结果表明：投资者羊群效应与股票超额收益显著正相关;大宗交易折溢价率与股票短期超额收益显著正相关;股票市场的伪羊群效应会减弱大宗交易对股票价格的短期影响。获取大宗交易定价信息的投资者理性与否决定了大宗交易定价对二级市场股票价格作用的强弱。进一步研究发现：沪深A股市场短期内伪羊群效应显著,长期内真羊群效应显著;这充分表明中国股票市场的资产定价相对合理,投资者处于有限理性状态。     

高管晋升与企业税负——来自中国地方国有上市公司的经验证据

本文选取2003—2014年中国沪深两市A股地方国有上市公司为样本,实证考察了企业税负承担与高管晋升之间的关系。研究发现,地方国有企业税负承担与高管晋升呈显著正相关关系,即积极的税负承担有助于增加高管晋升概率,存在税负晋升激励效应。进一步研究发现,税负晋升激励效应受企业层级和高管异质性的影响,省属国有企业、高管越年轻、任期越短,税负晋升激励效应越显著。本文从企业税负视角,发现了影响国有企业高管晋升的新证据,为完善国有企业高管考核机制提供有益的借鉴和启示。     

Order Imbalance in the FTSE Index Futures Market: Electronic versus Open Outcry Trading

Abstract:  This study examines trading activities before and after the transfer of the FTSE 100 index futures contract from open outcry to electronic trading. Daily order imbalance exhibits strong serial persistence in the electronic limit order market, but not in open-outcry trading. Both excess buying and selling reduce liquidity. In the electronic venue, prior market movements barely affect investors' buying or selling decisions. Excess buy orders do not generate any price impact, but sell orders do. Positive imbalances are more strongly autocorrelated than negative imbalances. No trading elements, such as order imbalance, volume, or open interest, are associated with volatility. Moreover, excess buying decreases volatility. Such evidence suggests that the development and growth of electronic trading has changed the dynamics of trading activities in many important ways.     

Short selling,margin trading,and the incorporation of new information into prices

Utilizing daily data on Chinese stocks' short selling and margin trading activities and intraday stock trade and quote data, we find a positive association between the degree of information efficiency of stock prices and the intensity of short selling and margin trading. Short selling (margin buying) escalates during the 5 days immediately before significant negative (positive) information events, which suggests short sellers (margin buyers) anticipate forthcoming news. Using the adverse selection component of the bid–ask spread as a proxy, we find that short selling and margin trading are associated with an improved information environment. Taken together, our empirical evidence supports the conjecture that short selling and margin trading in the Chinese market help stock prices incorporate new information more efficiently. Utilizing the unique Chinese regulation, we also examine the role of brokerages authorized for such trading and document a non-linear relation between pricing efficiency and the number of authorized brokerages.     

Institutional trading and stock returns

In this study, we explore the dynamics of the relation between institutional trading and stock returns. We find that stock returns Granger-cause institutional trading (especially purchases) on a quarterly basis. The robust and significant causality from equity returns to institutional trading can be largely explained by the time-series variation of market returns, that is, institutions buy more popular stocks after market rises. Stock returns appear to be negatively related to lagged institutional trading. A further analysis of the behavior of trading and the returns of the traded stocks reveals evidence that stocks with heavy institutional buying (selling) experience positive (negative) excess returns over the previous 12 months.     

Margin trading,short selling,and bond yield spread

Using a quasi-natural experiment, this study examines the effects of margin trading and short selling on bond yield spread in China. It finds that both margin trading and short selling can reduce bond yield spread. Additionally, it finds that margin trading lowers firms’ debt ratios and increases their credit ratings, which explains the reduced spread. In other words, margin trading can impact investors’ decisions by revealing positive information about a firm. Another finding is that short selling lowers the bond yield spread by decreasing earnings management, suggesting that short selling has an impact on investors’ decisions through its effect on corporate governance. Our results suggest that margin trading transmits positive information and short selling impacts firms’ policies. These results provide support for future regulations of margin trading and short selling.     

做空机制对我国股市波动性影响的实证分析

我国融资融券业务于2010年3月31日正式启动,而作为一种资本市场机制,做空机 制一直以来都饱受理论界和实务界的争议,做空机制对市场波动的影响尚未达成一致结论。本 文考察了做空机制与市场波动性之间的关系。研究发现：（1）在样本期间内,市场波动与做空 机制之间存在长期的稳定关系;（2）买空交易会在一定程度上增加市场波动,而卖空交易会 在一定程度上降低市场波动,但是二者的影响均有限;（3）综合来看,做空机制并不会引起证 券市场的异常波动,即使市场出现了大幅度的震荡,也不是由于卖空机制本身造成的;（4）本 文认为进一步完善做空机制尤其是卖空交易机制有助于稳定市场。本文结论对于评估做空机 制对市场波动的影响,防范经济冲击风险以及加强市场监管具有重要启示。     

卖空机制能够约束内部人减持吗？——基于融资融券制度的经验证据

本文以我国放松卖空管制为视角,探究其对内部人减持的影响。研究表明,卖空机制能够抑制企业内部人减持行为。机制分析发现,卖空对内部人减持的抑制作用是通过缓解股权高溢价实现的。进一步研究表明,卖空能够抑制大股东、董事以及管理层减持,但对监事减持无影响;卖空能够降低内部人减持的获利程度,并且在内部人减持动机更大时,对内部人减持的抑制作用更强;卖空通过约束内部人减持提升了股票定价效率,还有助于降低内部人增持行为。本文的研究结论丰富了卖空和内部人减持领域的文献,并对政府部门完善制度设计具有启示意义。     

Does long-term disequilibrium in stock price predict future returns?

We propose a trading strategy based on error correction term (ECT), the residuals from the cointegration relation between the levels of security and the market portfolio. We find that buying stocks in the top 10 % ECT and selling stocks in the bottom 10 % ECT generates 1.09 % a month for 6-month holding period over 1965–2005. The monthly return increases to 1.57 % when the above trading strategy is applied to stocks with insignificant cointegration with the market portfolio. This profit is robust to three and four factor models. Moreover, this profit is neither driven by small and illiquid stocks nor is the result of any inherent positive serial correlation.     

Business Cycles and Net Buying Pressure in the S&P 500 Futures Options

We analyse the cyclical behaviour and intraday pattern of net buying pressure in the S&P 500 futures options market. The results suggest that the net buying pressure of puts is counter‐cyclical and is more intense during contraction periods. The trading profits for selling put options during contraction periods thus far exceed those during expansion periods. Net buying pressure also exhibits an intraday pattern. Trading profits in the early trading sessions are higher than those for the rest of the day. In addition, we show that hourly‐basis hedging yields smaller profits than daily‐basis hedging, which suggests that the trading profits based on daily‐basis hedging may contain a risk premium associated with discretely rebalanced ‘risk‐free’ option portfolios.     

Terrorist attacks and oil prices: Hypothesis and empirical evidence

Using a unique dataset that merges terrorism activity with oil prices, this paper develops and tests the hypothesis that terrorist attacks predict oil prices. We develop three insights. First, we show that terrorist attacks have a positive effect on oil prices, but it is attacks originating from oil producer countries that most influence oil prices. Second, we devise trading strategies based on terrorist attacks and show that attacks, by signaling buying and selling in the market, beat a buy-and-hold strategy. We also show that a mean–variance investor who utilizes our terrorism-based forecasting model makes economically meaningful profits. Our analysis also shows that the effect of terrorism on oil prices operates via both the oil production and oil investment channels.     

Optimal execution with non-linear transient market impact

We study the problem of the optimal execution of a large trade in the propagator model with non-linear transient impact. From brute force numerical optimization of the cost functional, we find that the optimal solution for a buy programme typically features a few short intense buying periods separated by long periods of weak selling. Indeed, in some cases, we find negative expected cost. We show that this undesirable characteristic of the non-linear transient impact model may be mitigated either by introducing a bid–ask spread cost or by imposing convexity of the instantaneous market impact function for large trading rates; the objective in each case is to robustify the solution in a parsimonious and natural way.