Short sales,institutional investors and the cross-section of stock returns

Short-sale constraints are most likely to bind among stocks with low institutional ownership. Because of institutional constraints, most professional investors simply never sell short and hence cannot trade against overpricing of stocks they do not own. Furthermore, stock loan supply tends to be sparse and short selling more expensive when institutional ownership is low. Using institutional ownership as a proxy, I find that short-sale constraints help explain cross-sectional stock return anomalies. Specifically, holding size fixed, the under-performance of stocks with high market-to-book, analyst forecast dispersion, turnover, or volatility is most pronounced among stocks with low institutional ownership. Ownership by passive investors with large stock lending programs partly mitigates this under-performance, indicating some impact of stock loan supply. Prices of stocks with low institutional ownership also underreact to bad cash-flow news and overreact to good cash-flow news, consistent with the idea that short-sale constraints hold negative opinions off the market for these stocks.     

The return impact of realized and expected idiosyncratic volatility

We show that the negative relation between realized idiosyncratic volatility, measured over the prior month, and returns is robust in non-January months. Controlling for realized idiosyncratic volatility, we show that the relation between returns and expected idiosyncratic volatility is positive and robust. Realized and expected idiosyncratic volatility are separate and important effects describing the cross-section of returns. We find the negative return on a zero-investment portfolio that is long high realized idiosyncratic volatility stocks and short low realized idiosyncratic volatility stocks is dependent on aggregate investor sentiment. In cross-sectional tests, we find the negative relation is weaker for stocks with a large analyst following and stronger for stocks with high dispersion of analyst forecasts. The positive relation between expected idiosyncratic volatility and returns is not due to mispricing.     

Idiosyncratic risk and the cross-section of stock returns: Merton (1987) meets Miller (1977)

Merton [1987. A simple model of capital market equilibrium with incomplete information. Journal of Finance 42, 483–510] predicts that idiosyncratic risk should be priced when investors hold sub-optimally diversified portfolios, and cross-sectional stock returns should be positively related to their idiosyncratic risk. However, the literature generally finds a negative relationship between returns and idiosyncratic risk, which is more consistent with Miller's [1977. Risk, uncertainty, and divergence of opinion. Journal of Finance 32, 1151–1168] analysis of asset pricing under short-sale constraints. We examine the cross-sectional effects of idiosyncratic risk while explicitly recognizing the confounding effects that dispersion of beliefs and short-sale constraints produce in the Merton framework. We find strong support for Merton's [1987. A simple model of capital market equilibrium with incomplete information. Journal of Finance 42, 483–510] model among stocks that have low levels of investor recognition and for which short selling is limited. For these stocks, the relation between idiosyncratic risk and expected returns is positive, as predicted by Merton [1987. A simple model of capital market equilibrium with incomplete information. Journal of Finance 42, 483–510].     

Idiosyncratic volatility,fundamentals, and institutional herding: Evidence from the Japanese stock market

Using Japanese data from 1975 to 2003, we show that both institutional herding and firm earnings are positively related to idiosyncratic volatility. We reject the hypothesis that institutional investors herd toward stocks with high idiosyncratic volatility and systematic risk. Our results suggest that a behavior story may explain the negative premium earned by high idiosyncratic volatility stocks found by Ang et al. [Ang, Andrew, Hodrick, Robert J., Yuhang Xing, Xiaoyan Zhang, 2004. The cross-section of volatility and expected returns, Forthcoming Journal of Finance]. We also find that the dispersions of change in institutional ownership and return-on-asset move together with the market aggregate idiosyncratic volatility over time. Our results suggest that investor behavior and stock fundamentals may both help explain the time-series pattern of market aggregate idiosyncratic volatility.     

The dispersion anomaly and analyst recommendations

The main objective of this study is to distinguish whether the forecast dispersion anomaly is due to Miller’s (J Finance 32(4):1151–1168, 1977) overpricing hypothesis or idiosyncratic risk, by conditioning the sample on “buy” and “sell” consensus recommendations. Observations on the long and short possibilities provided to the investors by the analyst stock recommendations can help us infer on the impact of short sale constraints even though they are not directly observed. This study provides strong evidence that the impact of analyst forecast dispersion is more pronounced in the group of stocks that receive the least favorable recommendations in a given period, even after controlling for the idiosyncratic risk, Fama–French factors (J Financ Econ 33(1):3–56, 1993; J Financ Econ 116(1):1–22, 2015) and even short-sale constraints. These results are consistent with Miller’s (1977) hypothesis, according to which if short-sale constraints bind, high opinion divergence stocks become overpriced and hence have low subsequent returns.     

The skinny on the 2008 naked short-sale restrictions

On July 15, 2008, the US Securities and Exchange Commission announced temporary restrictions on naked short sales of the stocks of 19 financial firms. The restrictions offer a unique empirical setting to test Miller’s (1977) conjecture that short-sale constraints result in overpriced securities and low subsequent returns. Consistent with Miller’s overpricing hypothesis, we find evidence of a positive (negative) market reaction to the announcement (expiration) of the short-sale restrictions. Announcement returns are higher for firms that appear to be subject to more naked short selling in the days immediately preceding the announcement of the restrictions. The restrictions are successful in eliminating naked short sales for the restricted stocks, but naked short sales increase dramatically for a closely matched sample of financial firms during the restricted period. We also find that the restrictions negatively impact various measures of liquidity, including bid-ask spreads and trading volume. From a public policy perspective, our findings suggest that, at a minimum, policymakers should pause when considering further short sale restrictions.     

Idiosyncratic Volatility Covariance and Expected Stock Returns

Given that the idiosyncratic volatility (IDVOL) of individual stocks co‐varies, we develop a model to determine how aggregate idiosyncratic volatility (AIV) may affect the volatility of a portfolio with a finite number of stocks. In portfolio and cross‐sectional tests, we find that stocks whose returns are more correlated with AIV innovations have lower returns than those that are less correlated with AIV innovations. These results are robust to controlling for the stock's own IDVOL and market volatility. We conclude that risk‐averse investors pay a premium for stocks that pay well when AIV is high, consistent with our model.     

Idiosyncratic Risk,Investor Base,and Returns

Using four different proxies for a firm's investor base we demonstrate that idiosyncratic risk premiums are larger for neglected stocks and smaller or economically insignificant for visible stocks. Since neglected stocks have greater idiosyncratic volatility (IV), the total IV risk premium (price × quantity) for neglected stocks will be greater than that of visible stocks. Additionally, we find a positive size effect and negative beta effect after controlling for IV. Overall, our results provide strong support for Merton's theory that market segmentation induced by incomplete information is an important component of the influence of IV in the cross‐section of returns.     

The second moment matters! Cross-sectional dispersion of firm valuations and expected returns

Behavioral theories predict that firm valuation dispersion in the cross-section (“dispersion”) measures aggregate overpricing caused by investor overconfidence and should be negatively related to expected aggregate returns. This paper develops and tests these hypotheses. Consistent with the model predictions, I find that measures of dispersion are positively related to aggregate valuations, trading volume, idiosyncratic volatility, past market returns, and current and future investor sentiment indexes. Dispersion is a strong negative predictor of subsequent short- and long-term market excess returns. Market beta is positively related to stock returns when the beginning-of-period dispersion is low and this relationship reverses when initial dispersion is high. A simple forecast model based on dispersion significantly outperforms a naive model based on historical equity premium in out-of-sample tests and the predictability is stronger in economic downturns.     

Short-horizon incentives and stock price inflation

Do managerial incentive horizons have capital market consequences? We find that they do when short-sale constraints are more binding. Firms experience significant stock price inflation when their CEOs have short horizon incentives. The short-horizon CEOs sell more shares at inflated prices and generate greater abnormal trading profits. The stock price inflation is partly explained by greater earnings surprises and more positive investor reaction to the surprises. To inflate stock prices, short-horizon firms are more likely to employ income-increasing discretionary accruals. Consistent with theoretical predictions, all these effects are attenuated or statistically insignificant when short-sale constraints are less binding.     

Short-sale constraints and stock price crash risk: Causal evidence from a natural experiment

We examine the relation between short-sale constraints and stock price crash risk. To establish causality, we take advantage of a regulatory change from the Securities and Exchange Commission (SEC)’s Regulation SHO pilot program, which temporarily lifted short-sale constraints for randomly designated stocks. Using Regulation SHO as a natural experiment setting in which to apply a difference-in-differences research design, we find that the lifting of short-sale constraints leads to a significant decrease in stock price crash risk. We further investigate the possible underlying mechanisms through which short-sale constraints affect stock price crash risk. We provide evidence suggesting that lifting of short-sale constraints reduces crash risk by constraining managerial bad news hoarding and improving corporate investment efficiency. The results of our study shed new light on the cause of stock price crash risk as well as the roles that short sellers play in monitoring managerial disclosure strategies and real investment decisions.     

Comparing the information in short sales and put options

Prior work shows that both short sales and put options contain information about future stock prices. In this study, we compare the return predictability in short sales to the return predictability in put options. The motivation for this comparison is based on the theoretical argument that informed traders can choose between short sales and put options when establishing short positions in a particular stocks. Results in this paper suggest that the underperformance of stocks with high short-selling activity is approximately four times larger than the underperformance of stocks with high put-option activity. While stocks that are most likely to face binding short-sale constraints drive the underperformance caused by put-option activity, we still find that short sales are generally more informative about future prices.     

Investing in Chapter 11 stocks: Trading,value, and performance

We address questions about Chapter 11 stocks regarding their trading environment, fundamental value, and performance. First, there exists active trading for Chapter 11 stocks throughout the bankruptcy process. Second, equity value after filing is positively related to asset value, asset volatility, risk-free rate, and expected duration and is negatively related to liabilities. Furthermore, the return correlation between bankrupt stocks and their matching samples exhibits non-linearity similar to out-of-money call options. Third, investing in Chapter 11 stocks incurs large losses. Consistent with heterogeneous beliefs and limits to arbitrage, stocks with higher levels of information uncertainty and more binding short-sale constraints experience more negative returns.     

Arbitrage Asymmetry and the Idiosyncratic Volatility Puzzle

Buying is easier than shorting for many equity investors. Combining this arbitrage asymmetry with the arbitrage risk represented by idiosyncratic volatility (IVOL) explains the negative relation between IVOL and average return. The IVOL‐return relation is negative among overpriced stocks but positive among underpriced stocks, with mispricing determined by combining 11 return anomalies. Consistent with arbitrage asymmetry, the negative relation among overpriced stocks is stronger, especially for stocks less easily shorted, so the overall IVOL‐return relation is negative. Further supporting our explanation, high investor sentiment weakens the positive relation among underpriced stocks and, especially, strengthens the negative relation among overpriced stocks.     

Failures to Deliver,Short Sale Constraints,and Stock Overvaluation

Studying a large sample of publicly available data on failures to deliver, we find that stocks reaching threshold levels of failures become significantly overvalued. Where short sale constraints are especially binding, we report extreme overpricing and subsequent reversals. These findings support the overvaluation hypothesis, although the mispricing is likely to be difficult to arbitrage because of extreme shorting costs. In addition, threshold stocks with low short interest become more overvalued than threshold stocks with high short interest. This suggests that the level of short interest reflects supply‐side effects when the examination conditions on the difficulty of borrowing shares.     

Firm age and realized idiosyncratic return volatility in China: The role of short-sales constraints

This paper investigates how realized idiosyncratic return volatility changes with firm age in the Chinese stock market. By employing a sample of 26,676 firm-year observations of 2798 A-share listed Chinese firms from 2001 to 2019, we find that realized idiosyncratic return volatility is negatively associated with firm age. Further, we find that loosening short-sales constraints strengthens this negative association, and that heterogeneity of investor beliefs is the most likely mechanism driving the negative relation, rather than the alternative explanations of cash flow volatility and growth options. Our results are fairly consistent under two different measures of firm age, and are robust to a choice of two multiple-factor models (the Fama-French three-factor and five-factor models) as well as two data frequencies (daily and monthly) used to estimate realized idiosyncratic return volatility.     

Exchange-traded fund ownership and underlying stock mispricing

In response to the increasing proliferation of exchange-traded funds (ETFs), and a warning from the Wall Street hero Michael Burry that passive investing has put the stock market into ‘bubble’ territory, we examine the relation between stock ownership by ETFs and mispricing from 2002 to 2018. We find that increased ETF ownership induces overpricing in underlying stocks. We then identify three mechanisms for this relationship: the overpricing of stocks attributable to increased ETF ownership is stronger for stocks that experience an increase in passive ETF ownership; during periods characterised by high investor sentiment; and for illiquid stocks. Our results are robust to a battery of tests including alternative measures for all key variables and are not confounded by the global financial crisis. Additional analyses show that mispricing caused by ETF ownership change is not driven by firm fundamentals and does not exacerbate stocks' information environment around earnings announcement.     

Preferences for Stock Characteristics As Revealed by Mutual Fund Portfolio Holdings

This investigation of the cross-section of mutual fund equity holdings for the years 1991 and 1992 shows that mutual funds have a significant preference towards stocks with high visibility and low transaction costs, and are averse to stocks with low idiosyncratic volatility. These findings are relevant to theories concerning investor recognition, a potential agency problem in mutual funds, tests of trend-following and herd behavior by mutual funds, and corporate finance.     

Dispersion in beliefs among active mutual funds and the cross-section of stock returns

We propose a measure of dispersion in fund managers? beliefs about future stock returns based on their active holdings, i.e., deviations from benchmarks. We find that both the level of and the change in dispersion positively predict subsequent stock returns on a risk-adjusted basis. This effect is particularly pronounced among stocks with high information asymmetry and binding short-sale constraints. These results suggest that a subgroup of informed managers drives up the dispersion in active holdings when they place large bets after receiving positive private information. Binding short-sale constraints, however, prevent them from fully using their negative private information, leading to low dispersion in active holdings.     

Migrate or not? The effects of regulation SHO on options trading activities

In this study, we investigate the effects of stock short-sale constraints on options trading by exploiting two US Securities and Exchange Commission rule changes under Regulation SHO: Rule 203 (locate and close-out requirements) and Rule 202T (temporary removal of short-sale price tests). We find that stock short selling activities decrease (increase) significantly after Rule 203 (Rule 202T) implementation, supporting the validity of Rule 203 (Rule 202T) as an exogenous increase (decrease) in short-sale constraints. Options volume increases significantly after Rule 203 went into effect and the result is more pronounced among firms with lower levels of institutional ownership and smaller options bid-ask spreads. Therefore, the evidence from Rule 203 suggests that investors may use options as substitutes for stock short sales when short selling is less feasible or more costly due to the locate and delivery requirements. In contrast, we find no significant change in the options trading volume of pilot stocks during the pilot program of Rule 202T. Overall, our results indicate that the impact of short-sale constraints on options trading varies with the types of constraints affected.