Short-sale constraints and stock price informativeness

Morck, Yeung, and Yu (2000), in their pioneering study of international differences in stock price synchronicity, emphasize the effect of market development on investors' ability to incorporate firm-specific information into prices. We use a unique institutional feature in the Hong Kong market to investigate one of the important tools investors use to do this and hence reduce stock price synchronicity: short selling. Examining the cross-sectional and time-series variation in short-sale constraints in the Hong Kong market, we find that after the removal of short-sale constraints, stock prices become more informative and move less in tandem with the market.     

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.     

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.     

Options, short-sale constraints and market efficiency: A new perspective

This paper undertakes a new investigation of the potential for options to mitigate short-sale constraints. I find that option introduction alleviates 79% of the price adjustment efficiency disparity between short-sale constrained and unconstrained stocks in relation to negative news. No significant improvement in adjustment efficiency is found in response to positive information. These results are robust to controls for endogeneity biases associated with the option introduction selection process. Further, I find evidence that post-option improvement in efficiency is similar in relation to private and public information. This suggests that short-sale constraint effects stem, at least in part, from an irrational, optimism bias or another behavioral source as suggested theoretically by Miller (1977). Collectively, these results suggest that options act as an effective substitute to short-sales, significantly contributing to the informational efficiency of the market.     

The Valuation Impact on Distressed Residential Transactions: Anatomy of a Housing Price Bubble

Most previous empirical studies on foreclosure price discounts are based on data from housing-markets during periods of relative stability (Baton Rouge, Louisiana; Arlington, Texas; and Las Vegas, Nevada in 1980s and 1990s). The few studies with sample periods containing the Liquidity Crisis of 2008 were all focused on the Las Vegas market and even fewer studies have examined the pricing implications of short sale transactions. This study examines the discounts associated with foreclosure and short sale status in the Fresno, California from 2006 to 2010, a time period containing significant housing price volatility. Generally, we find approximately 20 % and 13 % discounts for foreclosure transactions and short sale transactions, respectively. These discounts remain consistent even after controlling for endogeneity of time-on-the-market and self-selection bias. We also document that both the foreclosure and short-sale discounts are time varying based on market conditions. Both foreclosure and short-sale discounts increase from 2008 to 2009 and decrease in 2010. Also, the foreclosure status decreases time on the market while the short-sale status increases time on the market.     

Short selling of ADRs and foreign market short-sale constraints

We examine the effect of home market short-sale constraints on securities that also trade in other countries that have more liberal short-sale rules. In particular, we focus on the case of ADRs traded in the US, as in some cases, the home markets of these ADRs prohibit short selling. We find that short sellers more heavily trade ADRs from countries where short selling is prohibited than from markets where short selling is allowed. Furthermore, we find that the greater levels of short selling in ADRs with binding home-market constraints is driven by stocks with greater dispersion of investors’ opinion, low fundamentals-to-price ratios, and recent price increases. Our results support the hypothesis that short sellers target ADRs with home market short-sale constraints because these ADRs are more often subject to temporary misvaluation.     

Liquidity as a choice variable: a lesson from the Japanese government bond market

In Japan, almost identical government bonds can trade at largeprice differentials. Motivated by this phenomenon, we examinethe issue of the value of liquidity in markets for risklesssecurities. We develop a model of an issuer of bonds, a marketmaker, and heterogeneous investors trading in an incompletemarket. We show not only that divergent prices for similar securitiescan be sustained in a rational expectations equilibrium butalso that this divergence may be optimal from the perspectiveof the issuer. Price segmentation is possible because agentshave a desire to trade, but short-sale restrictions limit theirtrading strategies and prevent them from forcing bond pricesto be equal. Restricting the form of market making to excludeprice competition and unregulated profit maximization is alsonecessary to sustain price segmentation. The optimality of segmentationfrom the issuer's standpoint arises because of the issuer'sability to charge for the liquidity services provided to theinvestors.     

Information-Based Trading and Price Improvement

Abstract:  In this study we test the information hypothesis of price improvement. Our results show that price improvement is negatively related to both the probability of information-based trading and the price impact of trades. We interpret these results as evidence that liquidity providers selectively offer price improvements according to the information content of trades. We also show that liquidity providers offer greater (and more frequent) price improvements when they are at the NBBO, and for stocks with wider spreads, fewer trades, or smaller trade sizes relative to the quoted depth. Buyer-initiated trades receive smaller (larger) price improvements than seller-initiated trades on the NYSE (NASDAQ).     

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.     

IPO pricing: a case of short-sale restrictions and divergent expectations

Prior research shows that short-sale restrictions during an IPO lead to higher aftermarket prices. Using this and heterogeneous expectations on the factor pricing coefficient, our model sheds additional light on the impact of the short-selling constraint. Like prior research, short-sale restrictions in the IPO market lead to higher aftermarket prices. Importantly, our model predicts that this constraint leads to a different factor pricing coefficient than the analog under complete markets. Our empirical tests over an extended period of time support the model's predictions.     

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.     

It's SHO Time! Short-Sale Price Tests and Market Quality

We examine the effects of the Securities and Exchange Commission (SEC)-mandated temporary suspension of short-sale price tests for a set of Pilot securities. While short-selling activity increases both for NYSE- and Nasdaq-listed Pilot stocks, returns and volatility at the daily level are unaffected. NYSE-listed Pilot stocks experience more symmetric trading patterns and a slight increase in spreads and intraday volatility after the suspension while there is a smaller effect on market quality for Nasdaq-listed Pilot stocks. The results suggest that the effect of the price tests on market quality can largely be attributed to distortions in order flow created by the price tests themselves.     

Price Clustering in the U.S. Dollar/Taiwan Dollar Swap Market

Price clustering in financial markets is pervasive. Using transaction‐level data from the world's largest financial market, this study is the first to examine price clustering behavior in the foreign exchange swap market. In addition to existing hypotheses, we investigate new determinants of price clustering including the expected return, contract liquidity, and trader's identity. The results support both negotiation and price resolution hypotheses. We find a positive effect from the level of expected return on price clustering. Markets with greater liquidity experience reduced clustering. Transactions involving domestic banks have less clustering suggesting an information advantage over foreign banks.     

News release and the role of different types of investors

We examine how investors react to positive and negative news in the Chinese stock market. We show that positive news is followed by a reversal in stock price, while negative news reports are accompanied by a drift. Using a unique account-level dataset, we find that institutional investors' attention bias contributes to the market's absorption process for different types of news, which is different from the conclusion that the phenomenon is driven by retail investors in the U.S. market. We explain the differences between the two markets as the short-sale constraints induce the attention bias of institutional investors in China. Individual investors are not able to correctly judge the content of news reports, and act as a liquidity provider. We highlight the market regulation plays an important role in the process of investors analyzing information.     

Trade size clustering and the cost of trading at the London Stock Exchange

For the London Stock Exchange, this paper investigates differences in trading costs between market maker (off-book) and order book trades, in the context of clustering in trade sizes and prices. We report several substantial findings. Even after controlling for differences in trade size, the realised spread measure is lower for off-book trades. For the order book, trade size clustering is not associated with differences in transaction costs nor with differences in the information content of trades. For the off-book market, trades in clustered (popular) sizes carry significantly more information than non-clustered trades. Despite the significant differences in the price impact estimates between the order book and off-book, we show that traders placing large orders off-book are still better off than trading via the order book as they benefit from a large discount from the current midpoint price. Additionally, we highlight that price and size clustering tend to occur simultaneously rather than being substitutes in this market setting.     

Short-selling bans and institutional investors' herding behaviour: Evidence from the global financial crisis

The literature on short-selling restrictions focusses mainly on a ban's impact on market efficiency, liquidity and overpricing. Surprisingly, little is known about the effects of short-sale constraints on herd behaviour. Since institutional investors have come to dominate mature stock markets and rely extensively on short sales, constraining these traders may influence the asset pricing process. We investigate six stock markets that faced bans during the recent global financial crisis. Our empirical evidence shows that short-selling restrictions exhibit either no influence on herding formation or induce adverse herding. This implies a higher dispersion of returns around the market compared to rational asset pricing, which can be interpreted as an increase in uncertainty among stock market investors.     

Incomplete-information capital market equilibrium with heterogeneous expectations and short sale restrictions

This article extends Merton's (1987) asset-pricing model under incomplete information to consider the situation when investors' beliefs are divergent and short selling is restricted. The article finds that the diversity of beliefs increases the mean variance inefficiency of the market portfolio and the shadow cost of information. However, the inefficiency of the market portfolio due to divergent beliefs is mitigated by short-sale restrictions. The article also finds that the effect of firm size is intertwined with the residual return variance risk. Consistent with the findings of Levy (1978) and Carroll and Wei (1988), the residual return variance plays an important role in determining the risk and risk premium of each security. Finally, the shadow cost of information is larger and the equilibrium security return is higher when expectations are more diverse. And the effects of divergent beliefs on both information cost and required rates of returns are negatively related to the relative size of investor base for a particular security.     

Short-sale constraints and informational efficiency to private information: A natural experiment

Exploiting a regulatory change in short-sale constraints (Regulation SHO) as a natural experiment, this paper examines the effect of short-sale constraints on informational efficiency of stock prices to private information. I find that short-sellers act as informed traders prior to forthcoming analyst news and trade on negative private information. When short-sale constraints are relaxed for pilot stocks (treatment group), both trading volume and stock price sensitivity increase prior to the analyst announcement for bad news but not for good news, relative to that of nonpilot stocks (control group). The findings are consistent with the Diamond and Verrecchia model that predicts that short-selling increases the speed of adjustment of stock prices to private negative information. In the cross-section, the effect of Reg SHO is stronger in stocks of firms with weak and uncertain information environments (i.e., small firms and firms with high analyst forecast dispersion).     

Macroeconomic Announcements and the Distribution of Price-Endings in the U.S. Treasury Market

We investigate how new information impacts quote clustering in the bond market. We find that clustering, along with quote activity, price volatility and bid-ask spreads, increases sharply in the minutes following releases of macroeconomic news. Each returns to near-normal levels within the hour. Effects are strongest for more liquid on-the-run notes and for the announcements typically associated with substantial information flow. The strong positive comovement of clustering, quote activity, price volatility, and bid-ask spreads supports the conclusion that innovations of these variables are endogenous to the arrival and incorporation of information into prices.     

Derivatives traders’ reaction to mispricing in the underlying equity

This article examines trading behavior in the options market conditioned on mispricing in the underlying stock. We investigate the price equilibrium between the observed equity asset and the options-implied synthetic share as well as the relative divergence between the two prices. We find a consistently positive relation between the level of stock mispricing and violations of the upper-boundary condition using derivatives, along with an increase in price divergence. To control for the effect of shorting limitations on mispricing, we further examine prices during the short-sale ban in 2008. The results hold and in many instances are more significant during the ban period. Given the persistent disequilibria between the synthetic and observed stock prices, we argue the results are evidence of informed trading in the derivatives market.