A faster estimation method for the probability of informed trading using hierarchical agglomerative clustering

The probability of informed trading (PIN) is a commonly used market microstructure measure for detecting the level of information asymmetry. Estimating PIN can be problematic due to corner solutions, local maxima and floating point exceptions (FPE). Yan and Zhang [J. Bank. Finance, 2012, 36, 454–467] show that whilst factorization can solve FPE, boundary solutions appear frequently in maximum likelihood estimation for PIN. A grid search initial value algorithm is suggested to overcome this problem. We present a faster method for reducing the likelihood of boundary solutions and local maxima based on hierarchical agglomerative clustering (HAC). We show that HAC can be used to determine an accurate and fast starting value approximation for PIN. This assists the maximum likelihood estimation process in both speed and accuracy.     

浅谈移动运营商城域接入网的融合演进

文章以近两年中移动在各省市大力发展建设全业务接入网为背景，从网络实情与接入传输技术特性出发，对未来3～5年移动运营商在接入网的融合演进方面提出明确目标及具体实施建议。     

R~2、异常收益与交易的信息成分

在CAPM回归中,低R^2的公司的价格是否更有效地反映了公司的特质信息在学术界始终存在争论。在R^2与公司特征变量的横截面检验基础之上,我们通过一个零成本投资组合考察了两个竞争性的理论。结果发现,（1）R^2与公司信息环境有显著关系,而且对于市场信息反应不够有效的公司,R^2会更低;（2）低酽股票组合短期的异常收益有更明显的时间序列可预测性和横截面风险,这说明在我国股市,低群代表了资产价格中更大的噪音成分;（3）股票的R^2与其价格中所包含的信息不对称或逆向选择成分呈负相关。     

Accounting conservatism in a setting of Information Asymmetry between majority and minority shareholders

Following LaFond and Watts (2008), we examine the relation between information asymmetry (as measured by PIN, probability of information-based trading) and accounting conservatism but focus on a country – Taiwan – whose institutional background is different from that of the United States. Due to the disparate degree of conservatism across the world, the conclusions of LaFond & Watts (2008) might not be universally applicable. Our findings support, in general, the applicability of their conclusion to a Taiwan data set. We find, however, that the effect of PIN appears weaker when auditor tenure is taken into account, thus supplementing their conclusions.     

信息不对称影响因素研究——以证券市场为例

本文通过引入带机制转换的向量自回归模型对信息交易概率模型进行改进,以描述信息不对称程度。通过面板回归的方法对中国证券市场信息不对称程度的可能影响因素进行了分析。实证结果显示,市场活跃度、市场预期和交易量对信息交易概率的影响比较大,市场微观结构和市场实际的信息状态对信息交易概率的影响比较小,但这四方面的解释因子对PIN都有不可替代的解释力,它们分别从不同的侧面解释了信息交易概率一半以上的信息。     

Does the Probability of Informed Trading Model Fit Empirical Data?

The probability of informed trading (PIN) is used widely as a measure of information asymmetry. Relatively little work has appeared on how well PIN models fit empirical trade data. We reveal structural limitations in PIN models by examining their marginal distributions and dependence structures represented by copulas. We develop a distribution-free test of the goodness-of-fit of PIN models. Our results indicate that estimated PIN models have generally poor fit to actual trade data. These results suggest that researchers should be cautious when PIN estimates are plugged into empirical models as explanatory variables.     

Is PIN priced risk?

Several recent papers assume that private information (PIN), proposed by Easley et al. [2002. Is information risk a determinant of asset returns? Journal of Finance 57, 2185–2221; 2004. Factoring information into returns. Working Paper, Cornell University], is a determinant of stock returns. We replicate Easley et al. (2002) and show that while PIN does predict future returns in the sample they analyze, the effect is not robust to alternative specifications and time periods. There is no evidence that PIN factor loadings predict returns or that PIN factor returns reflect future GDP growth. PIN exhibits no association with implied cost of capital derived from analysts’ earnings forecasts. Overall, our findings cast doubt on whether PIN reflects information risk systematically priced by investors.     

The characteristics of informed trading: Implications for asset pricing

This paper investigates the linkage of microstructure, accounting, and asset pricing. We determine the relationship between firm characteristics as captured by accounting and market data and a firm's probability of private information-based trade (PIN) as estimated from trade data. This allows us to determine what types of firms have high information risk. We then use these data to create an instrument for PIN, the PPIN, which we can estimate from firm-specific data. We show that PPINs have explanatory power for the cross-section of asset returns in long sample tests. We also investigate whether information risk vitiates the influence of other variables on asset returns. We develop a PPIN factor and show that it dominates the Amihud factor in asset returns. Our results provide strong support for information risk affecting asset returns in long sample tests.     

Informed trade,uninformed trade and stock price delay

The probability of informed trading (PIN), a measure of information-based trading risk, has been broadly applied to empirical studies on asset pricing. However, it is still controversial whether PIN measures exclusively the risk of firm-specific private information or it also captures the private interpretation of market wide public information. This article examines the relevance of PIN to the delayed response of stock prices to market-wide information. We find that PIN significantly explains individual stock price delay even controlling for size, liquidity and risk, and low-PIN stock prices adjust to market information more rapidly not only because of a notably high level of informed trading but also an even much higher level of uninformed trading. Our findings support the notion that PIN also captures the private skilled interpretation of public common factor information by sophisticated investors, and provide new empirical evidence on how information-based trading affects the speed at which stock prices adjust to information.     

一种高压大电流PIN管开关驱动器的设计

介绍了一种PIN管开关驱动电路。该电路采用了控制信号与高压源相隔离的方法,可 支持300 V以内的高压,并具有800 mA的电流驱动能力,驱动电路的开关切换时间小于 2.6 μs。通过对高压器件的防击穿保护,并增加适当的延时电路,大幅度提高了驱动 电路的工作稳定性。该电路可应用到高电压、大电流、高功率容量、高速切换的PIN管开关 中。