具有不完全信息的内部交易动态博弈

在Kyle模型中的线性均衡假设进行了修正的基础上,针对内部交易者只具有资产价值不完全信息情况,建立两期风险厌恶型内部交易均衡模型,并求得该模型的子博弈纳什均衡解.由此发现资产价值不完信息中噪音对市场干扰程度愈小(波动程度愈小),就愈有利于内部交易者的收益;内部交易者的交易就愈活跃;交易均衡价格包含资产价值信息就愈多.     

股指期货对现货市场微观结构影响研究

着眼于股指期货对现货市场微观结构的影响,基于2015-2017年三次股指期货交易机制重大调整前后两个月的1分钟高频数据,利用ACD-EGARCH模型对不同市场波动率背景下的股指期货是否改善现货市场微观质量进行了实证研究.文章的主要结论为:股指期货在不同市场波动率背景下均能降低现货市场波动率,且新进入的投机者比信息交易者贡献更高的波动率;而只在平稳市背景下,股指期货能增强现货市场流动性,在波动市背景下,股指期货吸引的信息交易者超过现货市场增加的非信息交易者,现货市场流动性减弱.建议在平稳市背景下恢复股指期货的常态化交易,但需要防范利好消息和投机者入市对市场波动率的冲击风险.     

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。     

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.     

认知偏差下的市场操纵和股价波动分析

基于非知情交易者操纵市场的假设,考虑交易者对基本面存在认知偏差,构建了市场操纵下的理性预期均衡模型,通过比较市场操纵出现前后价格的波动,分析谣言信号传播对股票价格的影响.结论表明:噪声信息在市场的传播过程中加剧了股票的波动,降低了价格中的信息含量,使股票价格偏离其基本面价值,产生了虚拟价值,随着跟随交易者数量的增多,股价的波动可能会更加剧烈,价格持续偏离.     

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.     

代表性启发式交易者市场微观结构

本文研究了一个市场,其中所有的交易者都是代表性启发式交易者,他们过于重视新信息和当前价格.代表性启发法增加了市场深度,增加了价格的信息量,降低了知情交易者的期望效用.启发式交易导致价格对新信息反应过度,知情交易者作为动量交易者的期望效用低于不知情交易者作为反转交易者的期望效用.在有内生噪声交易者的市场中,除了相似的结论外,代表性启发法增加了噪声交易并增加了价格波动性.     

基于鞅测度的流动性风险溢价的测算

研究了在一般市场条件下流动性风险的定价问题.首先借助金融数学和金融工程的无套利思想在鞅测度下对市场风险和流动性风险进行定价,通过等价测度变换,使可交易资产的贴现价值过程转化为鞅过程,得到了市场风险和流动性风险的市场价格,进而给出了流动性风险溢价的计算公式.得到的风险的市场价格在同一市场中对于所有可交易资产都是相同的,并且这一价格对于所有投资者也都是相同的,不会因投资者的风险厌恶水平的不同而不同.     

随机通胀风险下基于半鞅理论的最优投资策略

本文在半鞅理论框架下,构建包括可交易风险资产、不可交易风险资产和未定权益的金融投资模型。在考虑随机通胀风险和获取部分市场信息的情形下,研究投资经理人终端真实净财富指数效用最大化问题。运用滤波理论、半鞅和倒向随机微分方程(BSDE)理论,求解带有随机通胀风险的最优投资策略和价值过程精确解。数值分析结果发现,可交易风险资产最优投资额随着预期通胀率的增加而减少,投资价值呈先增后减态势。当通胀波动率无限接近可交易风险资产名义价格波动率时,通胀风险可完全对冲,投资人会不断追加在可交易风险资产的投资额,以期实现终端真实净财富期望指数效用最大化。研究结果为金融市场的投资决策提供更加科学的理论参考。     

指令驱动市场中的组合下单策略研究

已有研究一般直接假设指令驱动市场中的知情交易者总是选择市价单进行交易，本文则基于现实交易状况．建立了一个理论模型．分析拥有私有信息的知情交易者组合使用限价委托单和市价委托单的决策问题．具体给出了不同私有信息状态下知情交易者的组合下单选择。     

On the role of heterogeneous and imperfect information in a laboratory financial market

In this paper, we analyze the behavior of a group of heterogeneously informed investors in an laboratory asset market. Our experimental setting is inspired by Huber et al. (On the benefit of information in markets with heterogeneously informed traders: an experimental study, 2004). However, instead of their system of cumulative and exogenously given information structure, we introduce an information market where the traders can buy an imperfect prediction of the future value of the dividend with a maximum anticipation of four periods. The accuracy of the prediction decreases with the chosen time horizon, whereas its price remains constant. Our results confirm a non-strictly monotonic increasing value of the information.     

Information on jump sizes and hedging

We study a hedging problem in a market where traders have various levels of information. The exclusive information available only to informed traders is modelled by a diffusion process rather than discrete arrivals of new information. The asset price follows a jump–diffusion process and an information process affects jump sizes of the asset price. We find the local risk minimization hedging strategy of informed traders. Numerical examples as well as their comparison with the Black–Scholes strategy are provided via Monte Carlo.     

基于异质交易者定价模型的资产价格泡沫内生机理研究

资产价格泡沫等市场异常现象使得有效市场假说理论受到质疑,研究者们更多的是从行为金融学的角度对这些现象进行解释,认为是由市场投资者的非理性因素所造成的。本文考虑了市场中投资者决策的异质性,构建了含有长期基础投资者和短期技术投资者的异质交易模型,以说明在投资者均具有理性预期的条件下,有效市场假说理论同样可以解释泡沫的产生。具体而言,技术投资者的交易行为使价格产生波动,基础投资者的存在则对波动起到放大作用,并会进一步导致泡沫的出现,随着基础投资者所占的比例增大,泡沫膨胀的速度加快,由此导致市场的波动越剧烈。研究结果为市场监管者提供了有益的启示:与其设置壁垒限制技术投资者的加入及交易活动,不如让越来越多的技术投资者加入到市场中来,这样更有益于市场的稳定。     

交易者异质性与期货市场动态关系的仿真研究

本文构建了一个基于异质性交易者的投机性期货市场仿真模型,从交易者微观行为的角度分析市场价格的动态特征。市场中有限理性的交易者具有异质性信念和不同的学习能力。个体预期不断调整,市场根据密封拍卖机制出清,期货价格随之变化。仿真结果表明,价格的波动与市场中大投机交易者的活动密切相关。仿真能够再现期货价格波动高峰厚尾。长记忆等特征。噪声交易者在市场中的生存,取决于外部信息流对市场的影响过程以及其他交易者的行为.本文是采用计算金融学仿真方法研究衍生产品市场的一种尝试,也为此领域的研究者在模型的实现上提供了另外一种容易实现的途径。     

Trading volume in models of financial derivatives

This paper develops a subordinated stochastic process model for an asset price, where the directing process is identified as information. Motivated by recent empirical and theoretical work, the paper makes use of the under-used market statistic of transaction count as a suitable proxy for the information flow. An option pricing formula is derived, and comparisons with stochastic volatility models are drawn. Both the asset price and the number of trades are used in parameter estimation. The underlying process is found to be fast mean reverting, and this is exploited to perform an asymptotic expansion. The implied volatility skew is then used to calibrate the model.     

Optimal portfolio choice and stochastic volatility

In this paper we examine the effect of stochastic volatility on optimal portfolio choice in both partial and general equilibrium settings. In a partial equilibrium setting we derive an analog of the classic Samuelson–Merton optimal portfolio result and define volatility‐adjusted risk aversion as the effective risk aversion of an individual investing in an asset with stochastic volatility. We extend prior research which shows that effective risk aversion is greater with stochastic volatility than without for investors without wealth effects by providing further comparative static results on changes in effective risk aversion due to changes in the distribution of volatility. We demonstrate that effective risk aversion is increasing in the constant absolute risk aversion and the variance of the volatility distribution for investors without wealth effects. We further show that for these investors a first‐order stochastic dominant shift in the volatility distribution does not necessarily increase effective risk aversion, whereas a second‐order stochastic dominant shift in the volatility does increase effective risk aversion. Finally, we examine the effect of stochastic volatility on equilibrium asset prices. We derive an explicit capital asset pricing relationship that illustrates how stochastic volatility alters equilibrium asset prices in a setting with multiple risky assets, where returns have a market factor and asset‐specific random components and multiple investor types. Copyright © 2011 John Wiley & Sons, Ltd.     

应用微模拟方法分析交易费用对股票市场影响的研究

基于对中国股票市场的连续竞价交易机制和投资者构成特征的分析,本文构建了一个人工模拟订单驱动股票市场模型。模型能够得出一系列与实际股票市场一致的典型事实,如收益率分布的胖尾特征以及波动率的聚集等。通过在模拟实验中设定不同的交易费用约束,分析了不同程度的交易费用约束对股票市场的影响。结果表明,交易费用的增加会导致股票换手率的大幅下降;由于流动性不足,提高交易费用水平并不一定能够达到降低市场波动的目的。     

Partially informed noise traders

The single auction equilibrium of Kyle??s (1985) is studied, in which noise traders may be partially informed, or alternatively they can be manipulated. Unlike Kyle??s assumption that the quantity traded by the noise traders is independent of the asset value, we assume that the noise traders are able to correlate their trade with the true price. This has several implications for the equilibrium, one being that the informed trader??s expected profits decrease as the noise traders?? ability to correlate positively improve. In the limit, the noise traders do not lose on average, and the informed trader makes zero expected profits. When the correlation is negative, we interpret this as manipulation. In this case the insider makes the highest expected profits, and the informativeness of prices is at its minimum.     

A jump model for fads in asset prices under asymmetric information

This paper addresses how asymmetric information, fads and Lévy jumps in the price of an asset affect the optimal portfolio strategies and maximum expected utilities of two distinct classes of rational investors in a financial market. We obtain the investors’ optimal portfolios and maximum expected logarithmic utilities and show that the optimal portfolio of each investor is more or less than its Merton optimal. Our approximation results suggest that jumps reduce the excess asymptotic utility of the informed investor relative to that of uninformed investor, and hence jump risk could be helpful for market efficiency as an indirect reducer of information asymmetry. Our study also suggests that investors should pay more attention to the overall variance of the asset pricing process when jumps exist in fads models. Moreover, if there are very little or too much fads, then the informed investor has no utility advantage in the long run.