Short sales constraints and price adjustments to earnings announcements: Evidence from the Hong Kong market

This study examines how short sales constraints affect the stock price adjustment to the release of public information in the Hong Kong Stock Exchange. Using a unique feature of this market that allows us to directly investigate the impact of short sales restriction, we find the following. First, non-shortable stocks react more strongly to the publication of negative information than shortable stocks do. Second, non-shortable stocks are overpriced before negative earnings announcements. Hence, part of the strong market reaction of non-shortable stocks on announcement day could be due to the correction of such overpricing. Third, the prices of non-shortable stocks reverse following the announcement of negative information, suggesting that investors overreact to negative information on announcement day. Fourth, it takes longer for the prices of non-shortable stocks to adjust to negative earnings information. On the whole, our results support the research that finds short sales restrictions reduce the efficiency of stock markets.     

Short-Selling Prior to Earnings Announcements

This paper examines short‐sales transactions in the five days prior to earnings announcements of 913 Nasdaq‐listed firms. The tests provide evidence of informed trading in pre‐announcement short‐selling because they reveal that abnormal short‐selling is significantly linked to post‐announcement stock returns. Also, the tests indicate that short‐sellers typically are more active in stocks with low book‐to‐market valuations or low SUEs. The levels of pre‐announcement short‐selling, however, mostly appear to reflect firm‐specific information rather than these fundamental financial characteristics. We believe that these results should encourage financial market regulators to consider providing more extensive and timely disclosures of short‐selling to investors.     

Are Short Sellers Informed? Evidence from the 2007–2008 Subprime Mortgage Crisis

This paper examines the short selling activities around financial firms’ announcements of asset write‐downs during the 2007–2008 subprime mortgage crisis. We find that short sellers accumulate short positions prior to write‐down announcements, and that stocks experience significantly negative returns around such announcements. These results suggest that the return predictability of short interests is due to short sellers’ informational advantage. Furthermore, we show that short sellers increase their positions significantly in the announcement month and keep increasing their positions afterward, suggesting the feedback effect of the disclosed write‐downs on financial firms’ existing exposures. The valuable information contained in the short interest should encourage regulators to mandate stock exchanges disclose short selling activities more frequently.     

THE WEALTH EFFECTS OF TRACKING STOCK RESTRUCTURINGS

We provide a comprehensive examination of the post‐issue wealth effects of 29 completed tracking stock restructurings. We document that for the parent stock and for the combined firm, tracking stock restructurings lead to insignificant long‐term excess returns. However, we find that shareholders of tracking stocks realize significant post‐issue wealth losses. Unlike spin‐offs and carve‐outs, announcements of tracking stock restructurings are preceded by negative one‐year excess returns, and unlike the positive post‐issue long‐term excess returns to spin‐off stocks and the insignificant long‐term excess returns to carve‐out stocks, tracking stocks experience negative long‐term excess returns.     

卖空者与内幕交易——来自中国证券市场的证据

本文研究上市公司内部人减持、年报、诉讼、分析师评级、停复牌以及高送转等重大公告前后卖空交易行为的变化,系统考察卖空者是否参与内幕交易以及何种因素影响卖空者参与内幕交易,发现卖空率较高的股票具有较低的未来收益,表明卖空者拥有信息优势,属知情交易者;卖空者拥有非常精确的择时交易能力,在重大利空公告前显著增加卖空量,而在利好公告前则显著减少卖空头寸,表明卖空者作为知情交易者的信息优势源自内幕消息;公司内、外部投资者的信息不对称程度越低或公司所在地的法治水平越高,卖空者参与内幕交易的行为就越少。因此,监管机构应密切关注公司重大消息发布前后卖空量的异常变动,同时,完善信息披露规则、健全证券分析师制度并强化法律法规的执行力度,才能有效防范卖空者参与内幕交易。     

The Calm before the Storm

I provide evidence that stocks experiencing unusually low trading volume over the week prior to earnings announcements have more unfavorable earnings surprises. This effect is more pronounced among stocks with higher short‐selling constraints. These findings support the view that unusually low trading volume signals negative information, since, under short‐selling constraints, informed agents with bad news stay by the sidelines. Changes in visibility or risk‐based explanations are insufficient to explain the results. This evidence provides insights into why unusually low trading volume predicts price declines.     

The relationship between short interest and stock returns in the Canadian market

This paper provides new insight into the relationship between short sales and stock market returns using a sample of stocks sold short in Canada. Short interest is defined in relation to trading volume. The results strongly support the assertion that short sales and excess returns are contemporaneously negatively correlated in Canada. The paper further finds that excess returns are more negative for small firms because the supply of shortable shares is constrained for these firms. Excess returns are less negative for stocks with associated options and convertible bonds. Importantly, the evidence is consistent with the proposition that informed traders short sell Canadian interlisted stocks in Canada, rather than the US, to exploit lower execution costs. Together the results suggest that less restrictive regulation of short sales will improve the efficiency of markets.     

Short-Sales Constraints and Price Discovery: Evidence from the Hong Kong Market

Short‐sales practices in the Hong Kong stock market are unique in that only stocks on a list of designated securities can be sold short. By analyzing the price effects following the addition of individual stocks to the list, we find that short‐sales constraints tend to cause stock overvaluation and that the overvaluation effect is more dramatic for individual stocks for which wider dispersion of investor opinions exists. These findings are consistent with Miller's (1977) intuition and other optimism models. We also document higher volatility and less positive skewness of individual stock returns when short sales are allowed.     

Short Sales Constraints and Momentum in Stock Returns

Abstract:   We show that stock characteristics identified by D'Avolio (2002) provide a reliable index of the mostly unobservable short sales constraints. Specifically, we find that this index is positively related to the level of short interest and to short selling costs implied by the disparity in prices in the options and stock markets, and is negatively related to future returns. Using this index, we show that the magnitude of momentum returns for the period 1984 to 2001 is positively related to short sales constraints, and loser stocks rather than winner stocks drive this result. We conclude that short sales constraints are important in preventing arbitrage of momentum in stock returns.     

THE DAY-OF-THE-WEEK ANOMALY: THE TORONTO STOCK EXCHANGE EXPERIENCE

This paper studies the day-of-the-week effect employing Canadian stock returns from January 1, 1975 to June 30, 1989. The study finds that, as opposed to large capitalization stocks, low capitalization (thinly-traded) stocks tend to have a larger negative return on Tuesday rather than on Monday - possibly due to lags in the price adjustment of these stocks following the release of negative information. Two main issues are investigated in an attempt to explain the day-of-the-week effect and its persistence over time: (a) the role of dividends, and (b) the role of information flows. The study finds that firms are much more likely to go ex-dividend on Monday than on any other day of the week; however, after correcting for the dividend effect, Monday's returns are still significantly negative. With respect to information flows, we find evidence consistent with an information-flows-related explanation of the day-of-the-week effect, particularly with the idea that macro announcements cause negative Monday returns.     

The Timing of Opening Trades and Pricing Errors

After demonstrating that a zero investment trading strategy that buys stocks with overnight returns below the market average and sells stocks with overnight returns above the market average earns more than 1% monthly profit, I demonstrate that this profit is greater for stocks that start trading more quickly than for other stocks. These results control for trading costs. The resulting pricing errors are a material portion of stock price volatility and suggest that a quick response to overnight information adds non‐information‐based stock volatility to stock prices.     

Can Short Restrictions Actually Increase Informed Short Selling?

We use the 2008 short selling regulations to test whether short sale restrictions can increase informed short selling. For the preborrow requirement, we find more negative price reactions to short interest announcements though no reliable increase in the price impact of short sales volume. For the stocks with banned short sales, we find an increase in the price impact of short sale volume though no reliable change in the price reaction to short interest announcements. Both restrictions, however, are associated with increased informed trading. Our results suggest that short restrictions will not reduce informed short selling and may actually result in an increase by increasing the proportion of informed short sellers..     

Are Stock‐for‐Stock Acquirers of Unlisted Targets Really Less Overvalued?

Extant studies assume that targets’ private ownership mitigates acquirers’ incentives and opportunities to finance acquisitions with inflated stocks. This view stems from the observation that, although the average stock‐for‐stock acquirer's merger announcement return is negative when the target is listed, it is positive when the target is unlisted. Accordingly, extant studies often suggest that announcements of stock‐for‐stock acquisitions of unlisted targets convey favorable private information about the acquirers. However, an analysis of stock‐for‐stock acquirers’ stock performance, abnormal accruals, net operating assets, and insider trading suggests the opposite. Acquirers of unlisted targets are generally more overvalued than acquirers of listed targets.     

Product line transformation,foreign sales,and firm value: Evidence from COVID-19 pandemic governance in urban China

Using a sample of Chinese firms, we examine stock market reaction to firms that announce a change in their product lines to those related to COVID-19 management (medical masks and ventilators, among others). We find the market reacts positively to the announcements. In addition, when a firm ordinarily has a large share of export sales, the stock market reaction is more salient, indicating that export sales provide a certification effect that positively signals investors. Additional analysis on moderating effects suggest that, conditional on foreign sales, prior experience with medical product lines or less uncertainty about supply availability enhances the cumulative announcement returns (CARs), while the adverse impact of firm size on CAR magnifies.     

The information content of director trading: Evidence from acquisition announcements in Australia

In response to the long-standing debate about the information content of director trading, this study investigates the implications of director stock trading before an acquisition announcement by the company. Using a sample of 1249 acquisition announcements made by Australian acquiring firms between 2003 and 2012, we find that the stocks of acquiring firms with net director sales tend to underperform those of acquiring firms with net director purchases or with no director trades. This evidence supports the notion that director trading conveys useful information about the quality of subsequent acquisitions. Further, the informational effect of net director sales is most pronounced for acquisitions where the method of payment is stock, implying that the acquiring firm's stock may be overvalued.     

Short sales and put options: Where is the bad news first traded?

Although the literature provides strong evidence supporting the presence of informed trading in both the option and the short equity markets, it is not clear which market attracts more informed trading. Using a unique dataset that covers intraday transaction data in the option and short equity markets, we investigate informed trading in a cross-market environment by explicitly studying the lead–lag relationship between the put net trade volume and short sales of the underlying stock. Our high frequency analysis shows that in general short sales contain more information. However, put options become more informative before the release of negative earnings announcements.     

Efficiency and the Bear: Short Sales and Markets Around the World

We analyze cross‐sectional and time‐series information from 46 equity markets around the world to consider whether short sales restrictions affect the efficiency of the market and the distributional characteristics of returns to individual stocks and market indices. We find some evidence that prices incorporate negative information faster in countries where short sales are allowed and practiced. A common conjecture by regulators is that short sales restrictions can reduce the relative severity of a market panic. We find strong evidence that in markets where short selling is either prohibited or not practiced, market returns display significantly less negative skewness.     

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.     

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.     

Short-sale inflow and stock returns: Evidence from Japan

Using a 10-year panel of flow-based information on stock borrowings and constructing a flow-based measure for shorting demand, I examine the relation between shorting demand and subsequent stock price movements. I find that the least heavily shorted stocks tend to outperform the most heavily shorted stocks and that this outperformance persists up to three months. In addition, using proxies for information asymmetry derived from the market microstructure literature, I find that this outperformance is not confined to stocks with high information asymmetry. These empirical findings indicate that short sellers act not only as informed investors who gain negative news but also as skillful investors who detect stock price deviations from fundamental values.