Investors and forecasters often extrapolate from past returns, but whether this reffects behavioral bias or efficient information processing remains unclear. We address this questionby inferring Chinese mutual fund managers’ market expectations from textual analysis oftheir commentaries and linking them to portfolio choices and performance. Extrapola-tion is state-dependent: it is stronger when growth is above trend and idiosyncratic riskis relatively more important. It is associated with weaker market timing and strongerstock picking, leaving overall performance unchanged. Our findings support a rational-inattention model of expectation formation, in which managers shift scarce attentionbetween aggregate and stock-speciffc information as the relative importance of differentrisks change.

This paper investigates whether Environmental, Social, and Governance (ESG) performance influences the stock idiosyncratic risk and extreme risk. We find that the ESG performance of listed companies significantly reduces the stock idiosyncratic risk and extreme risk. Furthermore, we identify that this mitigating effect is shaped by the nature of enterprise ownership and the firm life cycle. Through additional mechanistic analysis, we confirm that ESG performance affects the stock price volatility risk of listed companies by reducing levels of corporate earnings management and bolstering corporate reputation, thereby alleviating both idiosyncratic risk and extreme risk in stock prices.

Starting from the change in decision-makers’ risk attitude, which suggests “an increase in risk leads to a heightened tendency for risk aversion”, this study explores the nonlinear relationship between idiosyncratic risk and corporate cash holdings. Empirical analysis results indicate that, with the enhancement of decision-makers’ risk-averse degree, the marginal increase in corporate cash holdings presents an upward trend as idiosyncratic risk rises. Associated with the changes in managers’ risk attitude, the nonlinear relationship between idiosyncratic risk and corporate cash holdings becomes insignificant when the firm purchases directors’ liability insurance or is located in regions with better business environments. However, if the executives are older or hold academic titles, the increase in corporate cash holdings with the rise of idiosyncratic risk is more rapid.

This paper studies idiosyncratic risk of new ventures. An option-based model of a new venture with multistage investments and jumps is developed. Our model ex- plains (1) why new ventures?idiosyncratic volatility eventually decreases as they clear R&D investment stages and become mature ?rms ?the stage-clearing e¤ect; (2) the negative relation between jumps in value and subsequent idiosyncratic volatility ?the jump e¤ect; (3) the dynamics of idiosyncratic volatility under di¤erent schedules of staged venture capital investments; and (4) the e¤ect of di¤erent schedules of staged investments on ?rm valuation with the presence of jumps. Empirically, we develop a generalized Markov-Switching EARCH model to simultaneously capture structural changes in ?rms?idiosyncratic volatility and the relation between jumps and idiosyn- cratic volatility. Using a hand-collected dataset of early-stage biotech ?rms, we ?nd empirical evidence supporting the jump e¤ect and the stage-clearing e¤ect described by our model.

本文考虑一个面临经营性风险（非系统风险）的企业家，在给定的债务及企业所得税率下，如何通过消费平滑、企业资本投资、破产保护以及金融风险投资，实现消费效用最大化的公司金融问题。本文得到了非风险中性下企业资本价值的半闭式解及相应的最优经营策略和最优破产阀值。对应经典的资本资产定价（CAPM）理论，得到了企业家的期望收益率、贝塔系数、系统风险溢价和非系统风险溢价（idiosyncratic risk premium）。不同于传统观点，非系统风险溢价严格大于零。这些结论和数值计算表明，企业家的风险态度对企业资本价值、最优资本结构，资本投资策略、破产水平、贝塔系数、非系统风险溢价、期望收益率等具有显著的影响。

This paper examines the impact of idiosyncratic risk on the cross-section of weekly stock returns from 1963 to 2006. I use an exponential GARCH model to forecast expected idiosyncratic volatility and employ a combination of the size e§ect, value premium, return momentum and short-term reversal to measure relative mispricing. I ?nd that stock returns monotonically increase in idiosyncratic risk for relatively undervalued stocks and monotonically decrease in idiosyncratic risk for relatively overvalued stocks. This phenomenon is robust to various subsamples and industries, and cannot be explained by risk factors or ?rm characteristics. Further, transaction costs, short-sale constraints and information uncertainty cannot account for the role of idiosyncratic risk. Overall, these ?ndings are consistent with the limits of arbitrage arguments and demonstrate the importance of idiosyncratic risk as an arbitrage cost.

The evidence on the relation between idiosyncratic risk and future market return is at odds with the theory in Merton (1987). We argue that this is because conventional idiosyncratic risk measures are too noisy that consequently camou?age the true pricing relation suggested by the theory in empirical tests. To reduce the noise, we employ a random portfolio approach to construct an alternative aggregate idiosyncratic risk measure. Due to a high correlation between the noise components of the conventional idiosyncratic risk measure and our portfolio idiosyncratic risk measure, we include both measures simultaneously in a predictive regression, in which the conventional idiosyncratic risk measure helps to further reduce the noise in our portfolio idiosyncratic risk measure. We ?nd that both variables are signi?cant and jointly predict returns on the market with an adjusted R2 of 2%. Our results are very robust to all conventional control variables, sample periods, the size deciles.

The evidence on the relation between idiosyncratic risk and future market return is at odds with the theory in Merton (1987). We argue that this is because conventional idiosyncratic risk measures are too noisy that consequently camou?age the true pricing relation suggested by the theory in empirical tests. To reduce the noise, we employ a random portfolio approach to construct an alternative aggregate idiosyncratic risk measure. Due to a high correlation between the noise components of the conventional idiosyncratic risk measure and our portfolio idiosyncratic risk measure, we include both measures simultaneously in a predictive regression, in which the conventional idiosyncratic risk measure helps to further reduce the noise in our portfolio idiosyncratic risk measure. We ?nd that both variables are signi?cant and jointly predict returns on the market with an adjusted R2 of 2%. Our results are very robust to all conventional control variables, sample periods, the size deciles

This paper examines the impact of idiosyncratic risk on the cross-section of weekly stock returns from 1963 to 2006. I use an exponential GARCH model to forecast expected idiosyncratic volatility and employ a combination of the size effect, value premium, return momentum and short-term reversal to measure relative mispricing. I ?find that stock returns monotonically increase in idiosyncratic risk for relatively undervalued stocks and monotonically decrease in idiosyncratic risk for relatively overvalued stocks. This phenomenon is robust to various subsamples and industries, and cannot be explained by risk factors or ?rm characteristics. Further, transaction costs, short-sale constraints and information uncertainty cannot account for the role of idiosyncratic risk. Overall, these ?findings are consistent with the limits of arbitrage arguments and demonstrate the importance of idiosyncratic risk as an arbitrage cost.

The B-share markets in China, originally for foreign investors only, were opened to local investors in 2001. This reform was expected to improve the information efficiency in B-share markets, since local investors were supposed to be better informed than foreign investors. Meanwhile, we find that, after opening to local investors, B-share price synchronicity increases, and firm-specific return variation (idiosyncratic risk) decreases. Opening B-share markets to local investors fails to improve or even deteriorates the information capitalization of B-share prices. The findings may help us understand Chinese government’s policy making. For instance, in August 2007, Chinese government announced that Chinese citizens would be allowed in public to buy and sell Hong Kong stocks through special accounts with domestic commercial banks. But after hearing opinions from different entities, Chinese government decides to infinitely postpone this policy.