基于社会网络传递视角的内幕交易行为研究

依法从严打击内幕交易是我国金融监管的重要任务，也是推动资本市场高质量发展的重要保障。本文手工收集2007—2020年我国证监会公布的内幕交易行政处罚书中涉及的内幕信息和内幕交易数据，考察我国股市内幕交易的行为特征。研究发现：(1)从中美股市对比看，我国股市中消极型内幕信息占比更低，内幕信息泄露时间更长，内幕信息泄露期间和信息公告日的收益率绝对值更低。此外，我国股市中依托家人关系传递内幕信息的比例高于美国。(2)公司外部人尤其以朋友关系传递的内幕信息致使更高的内幕交易规模和收益率。(3)内幕交易显著提高了内幕信息泄露期间相关方的股票收益率。本文丰富了内幕交易学术文献，也为我国监管机构提升内幕交易监管效率提供了有益借鉴。     

卖空者与内幕交易——来自中国证券市场的证据

本文研究上市公司内部人减持、年报、诉讼、分析师评级、停复牌以及高送转等重大公告前后卖空交易行为的变化,系统考察卖空者是否参与内幕交易以及何种因素影响卖空者参与内幕交易,发现卖空率较高的股票具有较低的未来收益,表明卖空者拥有信息优势,属知情交易者;卖空者拥有非常精确的择时交易能力,在重大利空公告前显著增加卖空量,而在利好公告前则显著减少卖空头寸,表明卖空者作为知情交易者的信息优势源自内幕消息;公司内、外部投资者的信息不对称程度越低或公司所在地的法治水平越高,卖空者参与内幕交易的行为就越少。因此,监管机构应密切关注公司重大消息发布前后卖空量的异常变动,同时,完善信息披露规则、健全证券分析师制度并强化法律法规的执行力度,才能有效防范卖空者参与内幕交易。     

知情交易概率测算在内幕交易监管中的应用

内幕交易定义侧重信息分布状态,知情交易定义侧重信息认知状态,在立法和监管层面,内幕交易包含知情交易的内涵。信息优势是内幕交易监管困境的根源所在,知情交易概率模型从是否拥有信息的两种不同交易行为模式出发．有助于判断潜在的内幕交易行为,根据选取时间段变量、事件变量和财务指标变量的不同,为内幕交易监管选取重点目标提供参考。在监管实务操作中。强化信息核心、改革收盘机制、主张模糊界定等是必要的手段。     

内幕交易、股价信息含量与市场监管效力——基于中国A股市场的分析北大核心CSSCI

本文针对非法内幕交易对股价信息含量的影响进行实证检验,研究表明:就整体而言,内幕信息通过买卖双向非法内幕交易使交易发生日的股价信息含量显著提高,加剧市场信息不对称程度;并购重组类的内幕信息对内幕交易发生日的股价信息含量的影响最显著,而经营合作投资类的内幕信息影响最不显著;从对内幕交易监管的视角,现行实施的监管法规无法有效遏制由内幕交易造成的市场信息不对称性,且笼统的'盈罚比'监管方法无法有效遏制对公众投资者利益影响最大的内幕交易行为,监管机制有效性仍不足.     

证券市场内幕交易的识别与防控——基于我国法律框架下的路径分析

有效识别和防控内幕交易对维护资本市场的健康发展具有重要现实意义.只要内幕信息知情人或者非法获取内幕信息人在内幕信息敏感期内从事或者明示、暗示他人从事,或者泄露内幕信息导致他人从事了与该内幕信息有关的证券交易活动,内幕交易行为即告成立.本文提出的“五步锁定法”识别系统可以有效地识别内幕交易行为.加强内幕信息知情人的管理、提高对内幕信息传播途径的取证能力、增强对内幕交易的监管力量以及加大对内幕交易的处罚执行力度等措施构成了有效防止内幕交易行为发生的防控体系.     

新形势下并购重组中证券内幕交易的实证研究

防范证券内幕交易是市场监管的主要目标之一。当前,并购重组业已成为证券市场内幕交易行为频发的一个重要环节,不仅有少数公职人员卷入其中,内幕信息知情人士的范围也呈现愈加多样化的趋势。据此,监管方应当减少审批环节,提高披露效率,完善相关立法,加大惩处力度,运用民事、行政、刑事手段的合力共同打击这一违法违规行为,遏制我国证券市场内幕交易愈演愈烈的态势。     

并购重组过程中的信息泄露与财富转移北大核心CSSCISSCI

本文利用机构与个人投资者的持仓比例数据,分析检验了并购重组中存在的信息泄露问题与财富转移效应。实证结果表明,上市公司首次披露并购重组公告前,存在严重的信息泄露现象,机构投资者在交易时机与交易对象的选择上都明显占有优势,直接导致了不同投资者间出现显著的财富转移效应。进一步的分析还发现,信息泄露的现象在机构投资者持股比例较高的公司更容易出现,而在分析师关注程度较高、资产规模较大的公司则较少出现。这些发现有助于人们了解并购过程中存在的信息泄露现象,辩证地看待机构投资者所扮演的角色,并探寻了信息泄露在不同类型企业中存在的可能性,这对改进监管层政策法规、规范企业信息披露制度以及保护中小投资者利益都有着重要的启示作用。     

我国股票市场内幕交易行为分析

本文以中国证监会公布的内幕交易行政处罚公告为数据来源,从数量和主导者结构上分析我国股市内幕交易行为的现状,并从伦理、制度和监管三个层面分析内幕交易行为,最后提出相应的政策建议。     

我国股票市场内幕交易行为分析

本文以中国证监会公布的内幕交易行政处罚公告为数据来源,从数量和主导者结构上分析我国股市内幕交易行为的现状,并从伦理、制度和监管三个层面分析内幕交易行为,最后提出相应的政策建议。     

股权集中度与证券市场的倒U型内幕交易曲线

本文从上市公司股权集中度的视角研究证券市场内幕交易行为,通过对信息的产权分析,提出了倒U型的内幕交易曲线.实证研究也发现,随着股权集中度的逐渐增加,上市公司内幕交易的严重程度也会相应增加.然而,当股权高度集中时,第一大股东制衡机制将发挥作用,内幕交易严重程度会有所减轻.内幕交易严重程度与股权集中度总体上呈现出倒U型曲线关系.这个结果也为内幕交易监管确定了重点的监管范围,能有效提高监管效率并节省监管成本.     

Insider trading,future earnings,and post-earnings announcement drift

This paper examines the association between insider trading prior to quarterly earnings announcements and the magnitude of the post-earnings announcement drift (PEAD). We conjecture and find that insider trades reflect insiders’ private information about the persistence of earnings news. Thus, insider trades can help investors better understand and incorporate the time-series properties of quarterly earnings into stock prices in a timely and unbiased manner, thereby mitigating PEAD. As predicted, PEAD is significantly lower when earnings announcements are preceded by insider trading. The reduction in PEAD is driven by contradictory insider trades (i.e., net buys before large negative earnings news or net sells before large positive earnings news) and is more pronounced in the presence of more sophisticated market participants. Consistent with investors extracting and trading on insiders’ private information, pre-announcement insider trading is associated with smaller market reactions to future earnings news in each of the four subsequent quarters. Overall, our findings indicate insider trading contributes to stock price efficiency by conveying insiders’ private information about future earnings and especially the persistence of earnings news.     

市场操纵降低了中国股票市场的信息效率吗——来自沪市A股高频交易数据的经验证据

本文以尾市交易操纵为研究对象,尝试对中国股票市场可疑的尾市操纵行为进行识别与监测,并基于监测结果实证分析市场操纵如何影响市场信息效率。具体来看,本文利用沪市A股2013-2018年的日内高频交易数据,基于股票尾市交易相关指标异常变化特征,构建了尾市交易操纵识别模型,实证检验了市场操纵对信息效率的影响。研究结果表明,市场操纵对信息效率存在不利影响,市场操纵后股票流动性和股票波动性的异常变化是影响信息效率的关键传导路径,上述结论在考虑内生性问题后依然稳健。此外,研究还发现,国有企业、上市公司信息披露质量较高的情形下,市场操纵对信息效率不利影响程度较小。     

The probability of informed trading and mergers and acquisitions

This paper investigates the role of the probability of informed trading (PIN) in mergers and acquisitions (M&A). We show that acquirers with higher PINs use more cash to finance their deals due to their higher cost of equity, and acquirers use more equity financing when acquiring targets with higher PINs to share the information risk with the target shareholders. We also find that acquirers and targets with higher PINs both experience higher announcement returns when cash financing is used, indicating that PINs are priced in the M&A market.     

Institutional stakeholdings and better-informed traders at earnings announcements

Utama and Cready [Utama, S., Cready, W.M., 1997. Institutional ownership, differential predisclosure precision and trading volume at announcement dates. Journal of Accounting and Economics 24, 129–150] use total institutional ownership to proxy for the proportion of better-informed traders, an important determinant of trading around earnings announcements. We argue that institutions holding small stakes cannot justify the fixed cost of developing private predisclosure information. Also, institutions with large stakes generally do not trade around earnings announcements since they are dedicated investors or face regulations that make informed trading difficult. However, institutions holding medium stakes have incentives to develop private predisclosure information and trade on it; we show that their ownership is a finer proxy for the proportion of better-informed traders at earnings announcements.     

Uncertainty triggers overreaction: evidence from corporate takeovers

Behavioural finance models suggest that under uncertainty, investors overweight their private information and overreact to it. We test this theoretical prediction in an M&A framework. We find that under high information uncertainty, when investors are more likely to possess firm-specific information, acquiring firms generate highly positive and significant gains following the announcement of private stock and private cash acquisitions (positive news) while the market heavily punishes public stock (negative news) deals. On the other hand, under conditions of low information uncertainty, when investors do not possess private information, the market reaction is complete (i.e. zero abnormal returns) irrespective of the type of acquisition. Overall, we provide empirical evidence that shows that information uncertainty plays a significant role in explaining short-run acquirer abnormal returns.     

Determinants of M&A success in the European insurance industry

This research analyzes the success of mergers and acquisitions (M&A) for European acquiring insurers using a stock market perspective. In contrast to previous papers that use an event study approach, our analysis is based on the stochastic dominance methodology, in which we analyze short and long term capital market reactions following an M&A announcement. In addition, we examine firm- and transaction-specific determinants associated with superior M&A success. Using a sample of 102 European insurance M&A transactions over the period 1993–2009, our results indicate that acquiring insurers are second-order dominated by their benchmark portfolio in the short term. In the long run, we find no evidence of stochastic dominance compared to their non-acquiring counterparts. Moreover, we find that geographically diversifying acquirers are rewarded by the market, and that transactions in which the acquirer and target have a business relationship before the M&A announcement outperform transactions without pre-M&A participation in the short-term. Finally, we detect a positive relationship between cash payment and acquirers’ M&A success.     

A logit model of retail investors' individual trading decisions and their relations to insider trades

Among the various external information sources that influence individual investors' trading decisions, no research has considered the important influence of insiders' transactions. Retail investors might copy the behavior demonstrated by insiders' trading; therefore, this study establishes an approach to estimate the buying probability for a certain stock by a certain investor at a certain point in time and analyzes whether insider trade reports influence this probability. Using a sample of more than 270,000 retail trades in Germany between 2008 and 2009, along with more than 3000 insider trades in the same period, we find evidence of copying of insiders' trades by retail investors. The basic mimicry hypothesis holds, even when we consider an information event hypothesis and an insider attention effect hypothesis as alternative explanations. A robustness test also supports the findings.     

Insider Trading and Corporate Information Transparency

Our study examines the relation between insider trading and corporate information transparency. We find a negative relation between firms’ information transparency and the economic significance of insider trading, including the amount of insider purchase and sale and the profitability of insider transactions. We also find a negative relation between information transparency and stock price reaction to news of insider trading, which suggests that increases in information transparency preempt insiders’ private information. Our study provides evidence consistent with firms’ transparency-enhancing activities decreasing information asymmetry between insiders and investors by revealing insiders’ private information to investors in a timely manner.     

An Empirical Analysis of Illegal Insider Trading

Whether insider trading affects stock prices is central to both the current debate over whether insider trading is harmful or pervasive, and to the broader public policy issue of how best to regulate securities markets. Using previously unexplored data on illegal insider trading from the Securities and Exchange Commission, this paper finds that the stock market detects the possibility of informed trading and impounds this information into the stock price. Specifically, the abnormal return on an insider trading day averages 3%, and almost half of the pre-announcement stock price run-up observed before takeovers occurs on insider trading days. Both the amount traded by the insider and additional trade-specific characteristics lead to the market's recognition of the informed trading.