信息不对称、过度自信与股价变动

信息传导的非同步和投资者情绪变化是股票市场的两个典型特征,前者会引发投资者之间出现信息不对称问题,后者主要体现为投资者过度自信,两者共同作用影响股票价格变动。本文将信息不对称和投资者过度自信情绪置于同一个分析框架,建立两阶段动态序贯定价理论模型研究现实市场上信息传导过程中股价变动的内在机制。结果表明:(1)面临新信息的进入,投资者对股票收益预期的调整与均衡价格之间具有正相关关系;(2)面临有利消息时,过度自信投资者比例越大,股票的均衡价格越高,投资收益将越低;面临不利消息时则相反;(3)随着过度自信投资者比例以及过度自信程度升高,市场风险溢价将下降;(4)投资者群体在信息传导过程中出现分化,对股价变动形成异质信念,未获取信息和获取信息但未出现过度自信的投资者认为股价被高估,获取信息且出现过度自信的投资者认为价格被低估,促使更多的交易,引发市场成交量和股价变动;(5)过度自信投资者比例与过度自信程度提高均会对市场效率产生正向影响,而对市场深度具有负向效应。最后,基于理论结果对非对称性和持续性等典型的市场波动性特征进行解释。     

The Asymmetric Wealth Effect in the US Housing and Stock Markets: Evidence from the Threshold Cointegration Model

Previous studies commonly use a linear framework to investigate the long-run equilibrium relationship between the housing and stock markets. The linear approaches may not be appropriate if adjustments from disequilibrium are asymmetric in both markets. Nonlinear adjustments are likely to be observed since the two markets respond rather differently to negative shocks where the stock market is more volatile but price rigidity is found in the housing market. In this paper, we firstly propose two hypotheses on the long-run equilibrium relationship of the US housing and stock markets, and then employ the threshold cointegration model to investigate the potential asymmetric relationships between the two markets. Our empirical results reveal that cointegration exists among the markets, but adjustments toward its long-run equilibrium are asymmetric. Further evidence points out that a rapid mean reversion occurs in one regime where the stock price outperforms the housing price, and no significant reversion is found in the other regime, supporting the hypothesis of the existence of an asymmetric wealth effect among the two markets in the US. Furthermore, evidence from the asymmetric vector error correction model shows that significant error corrections toward the equilibrium exist in the short run only when the stock price exceeds the real estate price by the estimated threshold level, reassuring the finding of the asymmetric wealth effect.     

Institutional investor information network,analyst forecasting and stock price crash risk

In this paper, we construct the information network of fund investors based on the theory of social relationship networks and examine its impact of fund information sharing with analysts on stock price crash risk. Our results show that private information sharing among institutional investors reduces crash risk. Further results show that fund information sharing can alleviate analyst optimism bias and improve analyst forecast accuracy, which further reduces stock price crash risk. Moreover, these identified effects are more pronounced in a bull market than a bear market. Our study contributes to the research on private information transmission in fund information networks, and provides a new perspective for recognizing the relationships among institutional investor behavior, analyst forecasting, and stock price crash risk.     

Risk A version and Information Structure: An Experimental Study of Price Variability in the Securities Markets

This study investigates the differences in the behaviors between the speculative investors and the conservative investors in two separate experimental markets. Although the market for speculators shows greater price volatility in both bid/ask spread within a trade as well as with intraperiod variances, it exhibits several desirable properties. Specifically, the price patterns tend to converge closer, and at a greater speed to either the prior information equilibrium price or the rational expectation equilibrium price. It also achieves better allocational efficiency. And, it is also less likely to be misled by potentially “false” price information.     

The Effects of Public Information with Asymmetrically Informed Short‐Horizon Investors

This paper analyzes the effects of public information in a perfect competition trading model populated by asymmetrically informed short‐horizon investors with different levels of private information precision. We first show that information asymmetry reduces the amount of private information revealed by price in equilibrium (i.e., price informativeness) and can lead to multiple linear equilibria. We then demonstrate that the presence of both information asymmetry and short horizons provides a channel through which public information influences price informativeness and equilibrium uniqueness. We identify conditions under which public information increases or decreases price informativeness, and when multiple equilibria may arise. Our analysis shows that public information not only directly endows prices with more (public) information, it can also have an important indirect effect on the degree to which prices reveal private information.     

Daily Stock Trading by Investor Type and Information Asymmetry: Evidence from the Korean Market

We examine the influence of trading by heterogeneous investors on information asymmetry in the Korean stock market, which includes domestic and foreign institutional investors and individual investors. In particular, we examine the relationship between the daily trading volume and the level of information asymmetry reflected in the stock price. The results reveal that high-volume daily trading by domestic institutional and individual investors increases the degree of information asymmetry in the short term, but is more evident for individual investors. Foreign institutional investors tend to mitigate the information asymmetry. Finally, our findings are robust to an alternative measure of investor trading.     

Ambiguous Information,Portfolio Inertia,and Excess Volatility

I study the effects of risk and ambiguity (Knightian uncertainty) on optimal portfolios and equilibrium asset prices when investors receive information that is difficult to link to fundamentals. I show that the desire of investors to hedge ambiguity leads to portfolio inertia and excess volatility. Specifically, when news is surprising, investors may not react to price changes even if there are no transaction costs or other market frictions. Moreover, I show that small shocks to cash flow news, asset betas, or market risk premia may lead to drastic changes in the stock price and hence to excess volatility.     

Public Information, IPO Price Formation, and Long-Run Returns: Japanese Evidence

The price formation process of JASDAQ IPOs is more transparent than in the United States. The transparency facilitates analysis of important issues in the IPO literature—why offer prices only partially adjust to public information and adjust more fully to negative information, and why adjustments are related to initial returns. The evidence indicates that early price information conveys the underwriter's commitment to compensate investors for acquiring and/or disclosing information. Offer prices reflect pre-IPO market values of public companies and implicit agreements between underwriters and issuers that originate well before the offering. Underadjustment of offer prices is substantially reversed in the aftermarket.     

International price and earnings momentum

In this paper, we find that price and earnings momentum are pervasive features of international equity markets even when controlling for data-snooping biases. For Europe, we show price momentum to be subsumed by earnings momentum on an aggregate level. However, this rationale can hardly be sustained on a country level. Also, the above explanation is confined to certain time periods in the USA. Since we cannot establish a decent relation between momentum and macroeconomic risks, we suspect a behavior-based explanation to be at work. In fact, we find momentum profits to be more pronounced for portfolios characterized by higher information uncertainty. Hence, the momentum anomaly may well be rationalized in a model of investors underreacting to fundamental news. Finally, we find that momentum works better when limited to stocks with high idiosyncratic risk or higher illiquidity, suggesting that limits to arbitrage deter rational investors from exploiting the anomaly.     

Short-sale refinancing and price adjustment speed to bad news: Evidence from a quasi-natural experiment in China

Short selling may accelerate stock price adjustment to negative news. However, the literature provides mixed evidence for this prediction. Using short-sale refinancing and a staggered difference-in-differences (DID) model, this paper explores the effect of short selling on stock price adjustment. Our results show that (1) short-sale refinancing improves the speed of stock price adjustment to negative news. This result holds after we control for endogeneity. (2) The positive relationship between short-sale refinancing and stock price adjustment speed is significant in subsamples of stocks with higher earnings management or lower accuracy of analyst forecasts, indicating that firms with more opaque information are more likely to be targeted by short sellers. In subsamples of stocks with a higher ownership concentration or lower ownership by institutional investors, short selling is more likely to increase the speed of stock price adjustment, indicating that ownership structure may influence negative news mining. (3) As short-sale refinancing exacerbates the absorption of bad news by stock prices, it increases crash risk. This study enriches the research on the economic consequences of short selling and provides empirical evidence supporting regulations on short selling in China.     

Auditors’ Liability,Investments, and Capital Markets: A Potential Unintended Consequence of the Sarbanes‐Oxley Act

To restore investors’ confidence in the reliability of corporate financial disclosures, the Sarbanes‐Oxley Act of 2002 mandated stricter regulations and arguably increased auditors’ liability. In this paper, we analyze the effects of increased auditor liability on the audit failure rate, the cost of capital, and the level of new investment. We focus on a setting in which, with imperfect auditing, a firm has better information than investors about its prospects and seeks to raise capital for new investments in a lemons market. The equilibrium analysis derives corporate reporting and investing choices by the firm, attestation opinions by the auditor, and valuation by rational investors. Three empirically testable predictions emerge: although increasing auditor liability decreases the audit failure rate and the cost of capital for new projects, it also decreases the level of new profitable investments.     

Sustainability priorities,corporate strategy,and investor behavior

Using a sequential experiment, this study examines whether integration of material environmental, social, and governance (ESG) priorities into corporate strategy impacts investors’ short‐ and long‐term stock price assessments and investment allocation. In our examination, we consider the potential moderating effect of financial performance. We find that integration of ESG priorities into strategy does not have a significant effect on investors’ price assessments or investment allocation. This is true regardless of the trend in the company's financial performance. Our results hold across various demographics and the levels of investment knowledge and investment experience. Investors’ perception of relevance and reliability of material ESG information, however, has a mediating effect on their long‐term price assessment and investment allocation. Overall, our findings suggest that any future requirements on disclosure of ESG information by regulators and standard setters should aim to improve investors’ perception of the relevance and reliability of that information.     

Do mandatory risk factor disclosures reduce stock price crash risk?

We test whether voluntary or mandatory risk factor disclosures (RFDs) in 10-K filings is associated with a reduction in stock price crash risk. We find that the level of mandatory RFDs in 10-K filings is associated with a reduction in stock price crash risk but find no similar relationship for voluntary RFDs. We exploit two exogenous shocks to mitigate endogeneity concerns that remain to be addressed in the literature. We investigate the moderators for this relationship and find the reduction is magnified among firms with higher information asymmetry, higher litigation risk, or better corporate governance. Overall, our findings identify a potential avenue to mitigate stock price crash risk and provide evidence that mandated RFDs contain useful information content and benefit investors.     

基于异质信号的资产价格学习机制及均衡演化路径

本文从金融市场指令交易机制出发,将市场投资主体分为市场追随者和自我相信者两类,分析了两类投资者面对由异质分析资产价值信号形成的市场价格的学习机制,且对交易量变化以及均衡价格的达成路径进行了研究。研究表明,单期价格均衡下市场仍存在资产交易,且投资者随着均衡价格期数增加和价格精度增大逐渐撤离市场,较大的市场追随者比重将滞后混合策略市场的价格均衡期数。     

Exploring the relationship between investor sentiment and price volatility

By performing Grey relation analysis, this study elucidates the relationship between investor sentiment and price volatility in the Taiwanese stock market. A sequential relationship is identified between investor sentiment and price volatility, and ranked according to order of importance. Analytical results show that short sales volumes may be an individual leading indicator useful in observing the effects of sentiment on price volatility, followed by open interest put/call ratios and trading volumes, and buy/sell orders. Institutional investors are related, to a lesser extent, to price volatility and sentiment. Qualified foreign institutional investors, or more rational investors, are the least influenced by price volatility, followed by securities investment trust companies and dealers. TAIEX options exert the strongest influence on sentiment during the study period, making them a valuable reference for gauging price volatility.     

Institutional investor horizon and stock price synchronicity: Do product market competition and analyst coverage matter?

This paper provides new insights into the relation between institutional investment horizon and stock price synchronicity and investigates whether this relationship depends on the intensity of product market competition and analyst coverage. Based on a sample of French listed companies, we find that long-term (short-term) institutional investors are associated with lower (higher) stock price synchronicity. The results also show that the negative effect of long-term institutional investors is more accentuated for firms in less competitive markets and with high analyst coverage. An additional analysis shows that the synchronicity reduction effect does not vary during the financial crisis. Overall, these findings suggest that unlike their short-term counterparts, long term investors reduce asymmetric information and help disseminate firm-specific information into stock prices.     

水信息披露、机构投资者与股价同步性

基于2010-2016年中国A股高水敏感行业的322家上市公司数据,实证检验水信息披露对股价同步性的影响,以及机构投资者的调节效应。研究表明：水信息披露对股价同步性的影响呈倒U型,且在民营企业样本中尤其显著。在国有企业样本中,机构投资者的加入能促使水信息披露更好地融入股价;在民营企业样本中,只有在高水信息披露水平下,机构投资者才能更好地发挥调节作用。     

Retail investor information demand – speculating and investing in structured products

We study the impact of retail investor information demand on trading in bank-issued investment and leverage structured products, which are specifically designed for retail investors. Stock-specific information demand positively predicts speculative trading activity. Furthermore, we find a positive relationship between market-wide information demand and order aggressiveness and order uncertainty for speculating and investing activity. Whereas information supply is associated with speculative long positions, information demand does not induce investors to be predominantly long or short. Finally, we do not find retail investor information demand to contribute to an upward price pressure on security prices. In contrast, information supply exerts negative price pressure. Overall, retail investor trading in individual stocks is much more strongly influenced by market-wide information demand instead of firm-specific information demand. This implies a low informational efficiency of retail investor speculation and investing activity.     

投资者理性预期、流动性约束与股价崩盘传染研究

“传染性”是股价崩盘三大基本特征之一,会加剧股价崩盘负面影响,甚至引发系统性金融风险,因此,本文重点关注股价崩盘传染机制研究。首先,本文基于两阶段理性预期均衡模型,提出股价崩盘传染两大假设,即投资者理性预期与流动性约束导致传染;其次,基于2000-2016年全球28个国家或地区资本市场数据,实证检验股价崩盘传染机制和传染渠道。研究显示:(1)投资者理性预期、流动性约束会导致股价崩盘发生传染;(2)股价崩盘事件会在资本市场关联国家或地区传染;(3)提高资本市场信息透明度、加强金融管制有助于降低受关联国家或地区股价崩盘传染。