完全信息下有限个风险喜好型内部交易者的交易行为研究

张首元和巩馥洲等,针对一类特定的混合交易策略研究了具有完全信息的两个内部交易者的行为特征.依据张首元所建立的具有完全信息的有限个内部交易者的类似模型,我们研究了风险喜好型内部交易者的行为特征.我们首次发现:这些内部交易者可能的均衡混合交易策略中分量的参数是相等的,因而其分量具有同分布性;当内部交易者的个数小于等于6时,混合均衡策略的参数具有存在唯一性;而当内部交易者的人数大于等于7时,由于市场的激烈竞争,导致了混合均衡策略不存在.进一步,利用数值模拟方法我们分析了该模型中经济金融变量的变化特征及其经济金融含义.     

具有内部交易的多头交易博弈

以Kyle的单期模型为基础,针对交易市场的参入者掌握的信息集,将交易者分为内部交易者、若干类型的外部交易者、噪声交易者和做市商.从而建立具有内部交易的多头交易博弈随机模型,并求得该模型的线性纳什均衡解.由此发现公共信息存在,有利于外部交易者和噪声交易者,却不利于内部交易者操纵交易市场,因此,公共信息的存在对市场稳定和发展具有重要意义.     

非对称信息证券交易的跨期动态博弈均衡解析

揭示了不对称信息条件下证券市场均衡的基本特征.Grossman和Stiglitz模型依据不知情交易者的弱理性,解析了证券交易的静态均衡状态.O'Hara模型增强了不知情交易者的理性,强调了市场均衡时的风险定价,但其命题的成立条件是相互矛盾的.认为不知情交易者信息收集和处理能力的提高会使决策更为理性,证券市场的均衡本质上是交易者的动态博弈均衡.依此思路,运用不完美信息的跨期动态博弈模型解析了非对称信息条件下证券交易者的精炼贝叶斯纳什均衡.结论显示出,市场失效的主要原因是交易者之间的信息分析能力不平衡,而不是信息不对称;市场流动性的决定因素不是信息不对称风险而是知情交易者与不知情交易者所研判的无风险收益率的差别.     

不完全信息下两个内部交易者的交易行为分析

当市场上存在两个拥有不完全信息的内部交易者时,研究了其对待风险的态度分别为风险喜好、风险中性与风险厌恶情况下模型在混合策略空间中离散时间的均衡解和高频交易下均衡的渐近行为特征,并分析了相关模型的经济金融学意义.     

信息优势、有限关注与知情交易者竞争交易

在具有一个风险资产的两期交易模型中,刻画了两类知情交易者:一个内部交易者和多个市场专家,内部交易者获得更精确的信息,而市场专家是有限关注的,根据投入的关注度评价获得的信息质量。通过求解线性均衡条件下关注度和市场竞争程度对订单流、流动性、期望收益和市场效率等市场微观特征的影响,结果表明:市场专家的交易强度随关注度的增大而增强,而内部交易者的交易强度随关注度的增大而减弱;市场流动性随着关注度的增大而增大;当市场专家数量较少时,市场专家的收益随着关注度的增大而增大,当市场专家数量较多时,市场专家的收益随着关注度的增大先增大然后缓慢降低。     

信息不对称下带有“随机压力”定价规则的连续时间模型

本文是对Back(1992)和Cho(2003)关于内部交易模型的拓展.在金融市场中一共有3类人:内部交易者,不知情交易者和做市商.考虑一类比Cho研究的模型更广的定价规则.主要用动态规划的方法,证明了当内部交易者是风险中性时,定价规则中"随机压力"消失,均衡价格还是仅依赖市场上累计交易量.相应地,本文的结论推广了Back和Cho在经典模型中的结论.     

内部交易者会进行信息共享吗？

在Kyle模型中引入两个异质的内部交易者,利用理论模型推导的方式探讨他们是否会进行信息共享.研究发现在均衡状态下,内部交易者的期望利润是关于信息共享数量的减函数.当两个内部交易者不分享任何信息时,他们的期望利润能达到最大值;内部交易者没有动机进行信息共享.     

内部交易者会进行信息共享吗?（英文）

在Kyle模型中引入两个异质的内部交易者,利用理论模型推导的方式探讨他们是否会进行信息共享.研究发现在均衡状态下,内部交易者的期望利润是关于信息共享数量的减函数.当两个内部交易者不分享任何信息时,他们的期望利润能达到最大值;内部交易者没有动机进行信息共享.     

套期保值者策略性交易和市场多重均衡

金融市场中,投资者为规避风险经常采取套期保值策略,降低因资产价值波动带来的风险.从金融市场微观结构理论出发,通过分析知情交易者交易策略和做市商定价策略对套期保值者交易的影响,构建了套期保值者策略交易模型.从模型和数值分析得出,套期保值者的策略性交易使市场具有产生多重均衡的可能:一种为套期保值者数量多,流动性高的均衡;另一种为套期保值者数量少,流动性低的均衡.其形成过程为套期保值者进入(退出)市场会引起其他套期保值者进入(退出)市场,形成预期自我实现现象,导致不同流动性下的均衡.     

中国新三板市场阶段性集合竞价制度的价格发现研究

市场微观结构理论表明交易机制对资产价格的形成过程具有重要影响。本文以中国新三板交易机制改革为背景,从理论上分析了阶段性集合竞价制度的市场出清过程。阶段性集合竞价制度的核心在于市场出清时间间隔的设定。本文构建了一个存在信息摩擦和知情交易者学习机制的集合竞价市场出清模型,讨论了市场出清时间间隔对价格发现效率、资产价值不确定性和流动性风险的影响。研究发现:(1)在完美信息条件下,如果对市场规模较大和价值波动率较高的资产设定较短的市场出清时间间隔,将会降低投资者的流动性风险,提升市场质量;(2)在不完美信息条件下,除市场规模和资产价值波动率之外,信息不对称程度和知情交易者比例也是影响最优市场出清频率的重要因素;(3)在不完美信息条件下,对价值波动率较低的资产缩短市场出清时间间隔才能降低流动性风险,这与完美信息条件下的结论相反。     

证券市场内幕交易有信息含量的临界点值推算

中国证券市场内幕交易的同时存在市场操纵行为,使得独立判断内幕交易的信息含量存在困难.为解决判断纯粹内幕交易是否具有信息含量问题,需要确定内幕交易具有信息含量的临界点值.采用我国证券市场内幕交易与操纵样本数据,先在操纵均衡点附近排除市场操纵的影响,然后推算出无消息、无操纵状态下证券随同大盘运动的理论增长路径,在此基础上比较基于内幕信息操纵和理论增长情况,通过设定与理论增长的倍数关系,推算纯粹内幕交易具有信息含量的临界点值:异常收益应大于3%.该值可以解释现有文献认为内幕交易有或没有信息含量的矛盾与争论.应用于中国内幕交易实际情况及与近年国际相关研究文献对照,临界点值得到支持.     

The informational content of insider trading disclosures: empirical results for the Polish stock market

In this paper, we try to answer the question as to whether insider trading disclosures convey valuable information to market participants, valuable in the sense of the profitability of an investment strategy that faithfully mirrors insider behaviour. Our interest in this subject is limited to the case of announcements concerning insider transactions issued over a 6 year-period on the Warsaw Stock Exchange (WSE). Initially, we use event study methodology to check whether insider trading disclosures are accompanied by a performance of stock returns as well as trading volume. Two different models generating expected returns (expected volume) are employed to verify the robustness of our results. The first of these is the regime switching model, with the results then being recalculated by using a GARCH-type model which seem to be most useful for dealing with some of the inconvenient statistical properties of stock return and trading volume data. Afterwards, a technique based on the reference return strategies is used to examine whether or not outsiders who imitate insider behaviour are able to profit from it. The major findings are as follows: firstly, announcements about the sale of stocks by insiders convey no information to market participants. Secondly, a statistically significant market response to insider disclosures of purchases of stocks in their own company can be observed in the three days prior to the announcement release for both return as well as trading volume series, and finally, outsiders who purchased stocks previously bought by insiders experience negative returns whereas outsiders disposing of stocks previously sold by insiders earned a return of 8.57% over the 6 month-period.      

Backward stochastic differential equations with enlarged filtration: Option hedging of an insider trader in a financial market with jumps

Insider trading consists in having an additional information, unknown from the common investor, and using it on the financial market. Mathematical modeling can study such behaviors, by modeling this additional information within the market, and comparing the investment strategies of an insider trader and a non-informed investor. Research on this subject has already been carried out by A. Grorud and M. Pontier since 1996, studying the problem in a wealth optimization point of view. This work focuses more on option hedging problems. We have chosen to study wealth equations as backward stochastic differential equations (BSDE), and we use Jeulin's method of enlargement of filtration to model the information of our insider trader. We will try to compare the strategies of an insider trader and a non-insider one. Different models are studied: at first prices are driven only by a Brownian motion and in a second part, we add jump processes (Poisson point processes) to the model.     

内部信息者的最小亏损风险策略

在一定的假设条件下,利用扩大信息流方法解决了跳扩散环境下内部信息者的最小亏损风险策略问题.首先构建了内部信息者最小亏损风险策略模型,证明了内部信息市场的完备性.然后利用风险资产价格的Markov性和鞅表示定理得到了线性损失函数下的最小亏损风险最优策略和相应的价值函数.     

具有比例摩擦金融市场的一般经济均衡与资产定价(英文)

本文建立具有比例摩擦金融市场的简单两时期模型．经济人具有均值－方差偏好,并且在交易金融资产的过程中支付交易费用．本文证明了两种金融资产的一般经济均衡与资产定价的基本估值公式．     

Asymmetric Information,Heterogeneous Prior Beliefs and Market Regulation

Acta Mathematicae Applicatae Sinica, English Series - This paper studies the trading behavior of an irrational insider and its influence on the market equilibrium in the presence of market...     

Insider trading equilibrium in a market with memory

We consider the Kyle-Back model for insider trading, with the difference that the classical Brownian motion noise of the noise traders is replaced by the noise of a fractional Brownian motion B ^H with Hurst parameter ${H>\frac{1}{2}}$ (when ${H=\frac{1}{2}, B^H}$ coincides with the classical Brownian motion). Heuristically, for ${H>\frac{1}{2}}$ this means that the noise traders has some ??memory??, in the sense that any increment from time t on has a positive correlation with its value at t. (In other words, the noise trading is a persistent stochastic process). It also means that the paths of the noise trading process are more egular than in the classical Brownian motion case. We obtain an equation for the optimal (relative) trading intensity for the insider in this setting, and we show that when ${H\rightarrow\frac{1}{2}}$ the solution converges to the solution in the classical case. Finally, we discuss how the size of the Hurst coefficient H influences the optimal performance and portfolio of the insider.     

Dynamic Markov bridges motivated by models of insider trading

Given a Markovian Brownian martingale Z, we build a process X which is a martingale in its own filtration and satisfies X₁=Z₁. We call X a dynamic bridge, because its terminal value Z₁ is not known in advance. We compute its semimartingale decomposition explicitly under both its own filtration F^X and the filtration F^X,Z jointly generated by X and Z. Our construction is heavily based on parabolic partial differential equations and filtering techniques. As an application, we explicitly solve an equilibrium model with insider trading that can be viewed as a non-Gaussian generalization of the model of Back and Pedersen (1998) [3], where the insider’s additional information evolves over time.