Information Sales and Insider Trading with Long-Lived Information

Fundamental information resembles in many respects a durable good. Hence, the effects of its incorporation into stock prices depend on who is the agent controlling its flow. Like a durable goods monopolist, a monopolistic analyst selling information intertemporally competes against herself. This forces her to partially relinquish control over the information flow to traders. Conversely, an insider solves the intertemporal competition problem through vertical integration, thus exerting tighter control over the information flow. Comparing market patterns I show that a dynamic market where information is provided by an analyst is thicker and more informative than one where an insider trades.     

Information Diversity and Complementarities in Trading and Information Acquisition

We analyze a model in which different traders are informed of different fundamentals that affect the security value. We identify a source for strategic complementarities in trading and information acquisition: aggressive trading on information about one fundamental reduces uncertainty in trading on information about the other fundamental, encouraging more trading and information acquisition on that fundamental. This tends to amplify the effect of exogenous changes in the underlying information environment. Due to complementarities, greater diversity of information in the economy improves price informativeness. We discuss the relation between our model and recent financial phenomena and derive testable empirical implications.     

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.     

Equilibrium Block Trading and Asymmetric Information

This paper investigates the existence of equilibria with information-based block trading in a multiperiod market when no investor is constrained to block trade. Attention is restricted to equilibria in which a strategic uninformed institution (i.e., one which is forced to rebalance its portfolio but is free to choose an optimal rebalancing strategy) is willing to trade a block rather than “break up” the block into a series of smaller trades. Examples of such equilibria are found and analyzed.     

证券交易的透明度与信息揭示制度：理论综述

证券交易过程中，交易信息的发布、扩散和传递方式对于各类市场参与者非常重要。目前关于信息揭示制度和交易透明度对市场运行效果的影响尚存在许多争议。本文讨论了交易透明度的含义、研究者和市场机构对于交易透明度的争论、交易透明度与市场绩效的关系，以及不同交易透明性的市场之间的竞争等问题，系统总结了目前与证券交易透明度和交易信息揭示有关的理论观点，以期把握交易信息揭示程度对市场产生的影响，以及由此引起的交易透明度对市场的运行效率产生的影响。     

信息透明度与散户的交易选择——基于深圳交易所上市公司的实证研究

股市的风险往往归因于散户的交易,大力发展机构投资者成为提高市场效率的不可挑战的信条。透过微结构数据的分析,本文发现散户交易存在过度自信特征,可能过度高估私有信息精确度,导致错误定价信息。分离了过度自信的因素后,本文发现信息透明度为散户交易的重要依据。更为重要的是本文发现,相对于散户而言,信息透明度对机构投资者交易的影响较低,说明了信息透明度对处于信息劣势的投资者具有更重要的现实意义。     

Information Aggregation via Contracting

When a group of investors with dispersed private information jointly invest in a risky project, how should they divide the project's profit? We show that a simple contract dividing profits in proportion to investors' risk tolerances may facilitate information aggregation by altering investors' risk-taking incentives when they decide on how investment strategies respond to private information. Our results provide a contracting-based approach for information aggregation, which is an alternative to learning from endogenous market variables (e.g., prices) via contingent schedules as seen in well-known rational expectations equilibrium models.     

Trading Volume, Information Asymmetry, and Timing Information

This paper investigates trading volume before scheduled and unscheduled corporate announcements to explore how traders respond to private information. I show that cumulative trading volume decreases inversely to information asymmetry prior to scheduled announcements, while the opposite relation holds for volume after the announcement. In contrast, trading volume before unscheduled announcements increases dramatically and shows little relation to proxies for information asymmetry. I investigate the behavior of market makers and find that they act appropriately by increasing price sensitivity before all announcements, implying that they extract timing information from their order books.     

Information Aggregation Bias and Samuelson's Dictum

Under the assumption of incomplete information, idiosyncratic shocks may not dissipate in the aggregate. An econometrician who incorrectly imposes complete information and applies the law of large numbers may be susceptible to information aggregation bias. Tests of aggregate economic theory will be misspecified even though tests of the same theory at the microlevel deliver the correct inference. A testable implication of information aggregation bias is “Samuelson's Dictum” or the idea that stock prices can simultaneously display “microefficiency” and “macroinefficiency;” an idea accredited to Paul Samuelson. Using firm-level data from the Center for Research in Security Prices, we present empirical evidence consistent with Samuelson's dictum. Specifically, we conduct two standard tests of the linear present value model of stock prices: a regression of future dividend changes on the dividend-price ratio and a test for excess volatility. We show that the dividend price ratio forecasts the future growth in dividends much more accurately at the firm level as predicted by the present value model, and that excess volatility can be rejected for most firms. When the same firms are aggregated into equal-weighted or cap-weighted portfolios, the estimated coefficients typically deviate from the present value model and “excess” volatility is observed; this is especially true for aggregates (e.g., S&P 500) that are used in most asset pricing studies. To investigate the source of our empirical findings, we propose a theory of aggregation bias based on incomplete information and segmented markets. Traders specializing in individual stocks conflate idiosyncratic and aggregate shocks to dividends. To an econometrician using aggregate data, these assumptions generate a rejection of the present value model even though individual traders are efficiently using their available information.     

Competition among Trading Venues: Information and Trading on Electronic Communications Networks

This paper explores the competition between two trading venues, Electronic Communication Networks (ECNs) and Nasdaq market makers. ECNs offer the advantages of anonymity and speed of execution, which attract informed traders. Thus, trades are more likely to occur on ECNs when information asymmetry is greater and when trading volume and stock‐return volatility are high. ECN trades have greater permanent price impacts and more private information is revealed through ECN trades than though market‐maker trades. However, ECN trades have higher ex ante trading costs because market makers can preference or internalize the less informed trades and offer them better executions.     

Information of Unusual Trading Volume

This article investigates the information content of stock unusual trading volume from the aspect of firm fundamental information revealed by both earnings formal announcements and preannouncements. By using the stock market data of China from the second quarter of 2003 to the end of 2015, this article provides evidence that, in general, stocks that experience unusually low trading volume over the week prior to earnings announcements have more unfavorable earnings surprises. However, because of the feature of mandatory pre-disclosure policy in China, this article further finds that the relation between unusually low trading volume and unfavorable earnings surprises only exists in the stocks without earnings preannouncements, because fundamental information is incorporated in the stock prices timely around preannouncements date. In addition, unusually low trading volume signals negative fundamental changes revealed by preannouncements, and this effect is more pronounced among stocks with higher short-selling constraints, but unusually high trading volume is value-irrelevant.     

Informed Trading When Information Becomes Stale

This paper characterizes informed trade when speculators can acquire distinct signals of varying quality about an asset's value at different dates. The most reasonable characterization of private information about stocks is that while information is long‐lived, new information will arrive over time, information that may be acquired by others. Hence, while a speculator may know more than others at a moment, in the future, his information will become stale, but not valueless. In an environment that allows for arbitrary correlations among signals, we characterize equilibrium outcomes including trading, prices, and profits. We provide explicit numerical characterizations for different informational environments.     

Government Intervention and Information Aggregation by Prices

Governments intervene in firms' lives in a variety of ways. To enhance the efficiency of government intervention, many researchers and policy makers call for governments to make use of information contained in stock market prices. However, price informativeness is endogenous to government policy. We analyze government policy in light of this endogeneity. In some cases, it is optimal for a government to commit to limit its reliance on market prices to avoid harming the aggregation of information into market prices. For similar reasons, it is optimal for a government to limit transparency in some dimensions.     

高管交易行为、信息不对称与公司治理

基于沪深股市高管交易行为信息披露,在对高管卖出行为短期市场效应研究基础上,进一步研究高管买入、卖出行为的短期和长期市场效应及其产生根源.结果发现,无论从短期还是长期来看,高管买入行为有显著为正的市场效应,而卖出具有显著为负的市场效应,并且交易量越大、日内交易次数越多,市场效应越强烈.进一步结合公司治理理论发现,终极控股股东控制权与现金流权分离导致更强的买入市场效应,而法制环境抑制了买入市场效应.     

Strategic Trading, Liquidity, and Information Acquisition

We study endogenous liquidity trading in a market with long-livedasymmetric information. We distinguish between public information,tractable information that can be acquired, and intractableinformation that cannot be acquired. Besides information asymmetryand noise, the adverse-selection spread depends on the diffusionof intractable information and on the interest rate. With endogenousliquidity trading, efficiency is lower than that implied bynoise-trading models. Liquidity traders benefit from the informationreleased through the insider's trades in spite of their monetarylosses. We study factors that affect the insider's informationacquisition decision, including the amount of intractable information,observability, and information acquisition costs.     

Information, Trading, and Product Market Interactions: Cross-sectional Implications of Informed Trading

I present a simple model of informed trading in which asset values are derived from imperfectly competitive product markets and private information events occur at individual firms. The model predicts that informed traders may have incentives to make information‐based trades in the stocks of competitors, especially when events occur at firms with large market shares. In the context of 759 earnings announcements, I use intraday transactions data to test the hypothesis that net order flow and returns in the stocks of nonannouncing competitors have information content for announcing firms.     

Volatility Information Trading in the Option Market

This paper investigates informed trading on stock volatility in the option market. We construct non-market maker net demand for volatility from the trading volume of individual equity options and find that this demand is informative about the future realized volatility of underlying stocks. We also find that the impact of volatility demand on option prices is positive. More importantly, the price impact increases by 40% as informational asymmetry about stock volatility intensifies in the days leading up to earnings announcements and diminishes to its normal level soon after the volatility uncertainty is resolved.     

Information, Trading Demand, and Futures Price Volatility

We examine the relation between futures price volatility and trading demand by type of trader in the Standard & Poor's (S&P) 500-stock index futures market. We find that volatility covaries negatively with signed speculative demand shocks but is positively related to signed hedging demand shocks. No significant relation between volatility and demand shocks for small traders is found. Our results suggest that changes in positions of large hedgers destabilize the market, whereas changes in positions of large speculators stabilize volatility. Consistent with models with asymmetrically informed traders, we find that large speculators are likely to possess superior forecasting ability, large hedgers behave like positive feedback traders, and small traders are liquidity traders.     

移民式投票

"背井离乡",是个很悲壮的词。不是迫不得已,人们不会离开故土。而这一幕,在今天的中国却不断上演。"移民潮"成为中国社会每个阶层关注的热点,而这一次,显然又不同于多年前的"下南洋""走西口""闯关东"