Volatility spreads and earnings announcement returns

Prior research documents that volatility spreads predict stock returns. If the trading activity of informed investors is an important driver of volatility spreads, then the predictability of stock returns should be more pronounced during major information events. This paper investigates whether the predictability of equity returns by volatility spreads is stronger during earnings announcements. Volatility spreads are measured by the implied volatility differences between pairs of strike price and expiration date matched put and call options and capture price pressures in the option market. During a two-day earnings announcement window, the abnormal returns to the quintile that includes stocks with relatively expensive call options is more than 1.5% greater than the abnormal returns to the quintile that includes stocks with relatively expensive put options. This result is robust after measuring volatility spreads in alternative ways and controlling for firm characteristics and lagged equity returns. The degree of announcement return predictability is stronger when volatility spreads are measured using more liquid options, the information environment is more asymmetric, and stock liquidity is low.     

The Impact of Trades on Daily Volatility

This article proposes a trading-based explanation for the asymmetriceffect in daily volatility of individual stock returns. Previousstudies propose two major hypotheses for this phenomenon: leverageeffect and time-varying expected returns. However, leveragehas no impact on asymmetric volatility at the daily frequencyand, moreover, we observe asymmetric volatility for stocks withno leverage. Also, expected returns may vary with the businesscycle, that is, at a lower than daily frequency. Trading activityof contrarian and herding investors has a robust effect on therelationship between daily volatility and lagged return. Consistentwith the predictions of the rational expectation models, thenon-informational liquidity-driven (herding) trades increasevolatility following stock price declines, and the informed(contrarian) trades reduce volatility following stock priceincreases. The results are robust to different measures of volatilityand trading activity. (JEL C30, G11, G12)     

Informed trading,information uncertainty,and price momentum

In this paper we investigate the effects of informed trading (PIN) and information uncertainty in determining price momentum. We find that trading strategies based on buying high-uncertainty good-news stocks and shorting high-uncertainty bad-news stocks work well when limited to high-PIN stocks, while stocks with low-PIN do not exhibit price continuations, even when the uncertainty level of those stocks is high. In contrast, momentum returns are always significant for high-PIN stocks, irrespective of information uncertainty. Overall, we show that the informed trading effect is both independent of and stronger than that of information uncertainty in determining price momentum.     

The January Anomaly: Effects of Low Share Price,Transaction Costs,and Bid-Ask Bias

The January effect is primarily a low-share price effect and less so a market value effect. In the recent 1977–1986 period, after-transaction-cost raw and excess January returns are lower on low-price stocks than on high-price stocks. Failure of informed traders to eliminate significantly large before-transaction-cost excess January returns on low-price stocks is potentially explained by higher transaction costs and a bid-ask bias. At the least, the January anomaly found in prior tests is not persistent, and thereby, not likely to be exploitable by typical investors.     

The Dividend Disconnect

Many individual investors, mutual funds, and institutions trade as if dividends and capital gains are disconnected attributes, not fully appreciating that dividends result in price decreases. Behavioral trading patterns (e.g., the disposition effect) are driven by price changes instead of total returns. Investors rarely reinvest dividends, and trade as if dividends are a separate, stable income stream. Analysts fail to account for the effect of dividends on price, leading to optimistic price forecasts for dividend‐paying stocks. Demand for dividends is systematically higher in periods of low interest rates and poor market performance, leading to lower returns for dividend‐paying stocks.     

Against the tide: the commencement of short selling and margin trading in mainland China

China's recent removal of short‐selling and margin trading bans on selected stocks enables testing of the relative effect of margin trading and short selling. We find the prices of the shortable stocks decrease, on average, relative to peer A‐shares and cross‐listed H‐shares, suggesting that short selling dominates margin trading effects. Contrary to the regulators' intention and recent developed market empirical evidence, liquidity declines and bid‐ask spreads increase in these shortable stocks. Consistent with Ausubel (1990), these results imply that uninformed investors avoid the shortable stocks to reduce the risk of trading with informed investors.     

Initial Public Offerings and Underwriter Reputation

This paper examined the returns earned by subscribing to initial public offerings of equity (IPOs). Rock (1986) suggests that IPO returns are required by uninformed investors as compensation for the risk of trading against superior information. We show that IPOs with more informed investor capital require higher returns. The marketing underwriter's reputation reveals the expected level of “informed” activity. Prestigious underwriters are associated with lower risk offerings. With less risk there is less incentive to acquire information and fewer informed investors. Consequently, prestigious underwriters are associated with IPOs that have lower returns.     

The information content of trading halts

We investigate the impact of trading halts of NYSE-listed stocks on informationally related securities that continue to trade during the period of the halt. Informational relationships are established for companies in the same four-digit SIC industry based on the correlation of returns, volume, volatility, and the adverse selection components of spreads. We find a significant liquidity impact on informationally related securities with spreads and price impact of trades having substantial increases. However, we also find that quoted depths, the number of trades, and trade volume significantly increase. Our results are consistent with the trading halt model of Spiegel and Subrahmanyam [2000. Asymmetric information and news disclosure rules. Journal of Financial Intermediation 9, 363–403] and with the informed trading model of Tookes [2008. Information, trading, and product market interactions: cross-sectional implications of informed trading. Journal of Finance 63, 379–413]. In addition, our results indicate that there is a common liquidity response of informationally related securities to firm-specific trading halts.     

Which past returns affect trading volume?

Anecdotal evidence suggests and recent theoretical models argue that past stock returns affect subsequent stock trading volume. We study 3,000 individual investors over a 51 month period to test this apparent link between past returns and volume using several different panel regression models (linear panel regressions, negative binomial panel regressions, Tobit panel regressions). We find that both past market returns as well as past portfolio returns affect trading activity of individual investors (as measured by stock portfolio turnover, the number of stock transactions, and the propensity to trade stocks in a given month). After high portfolio returns, investors buy high risk stocks and reduce the number of stocks in their portfolio. High past market returns do not lead to higher risk taking or underdiversification. We argue that the only explanations for our findings are overconfidence theories based on biased self-attribution and differences of opinion explanations for high levels of trading activity.     

Does Academic Research Destroy Stock Return Predictability?

We study the out‐of‐sample and post‐publication return predictability of 97 variables shown to predict cross‐sectional stock returns. Portfolio returns are 26% lower out‐of‐sample and 58% lower post‐publication. The out‐of‐sample decline is an upper bound estimate of data mining effects. We estimate a 32% (58%–26%) lower return from publication‐informed trading. Post‐publication declines are greater for predictors with higher in‐sample returns, and returns are higher for portfolios concentrated in stocks with high idiosyncratic risk and low liquidity. Predictor portfolios exhibit post‐publication increases in correlations with other published‐predictor portfolios. Our findings suggest that investors learn about mispricing from academic publications.     

Retail clientele and option returns

Does the retail clientele matter for option returns? By delta-hedging options and trading straddles, thus allowing a focus on volatility, this paper empirically shows that a higher retail trading proportion (RTP) is related to lower option returns. Long-short portfolios involving options on low and high RTP stocks generate significantly positive abnormal returns. The results suggest that retail investors speculate and pay a lottery premium on the expected future volatility, resulting in more expensive options with higher implied volatilities.     

Does Noninformative Text Affect Investor Behavior?

This article demonstrates that easily processed texts affect investor trading behavior even in the absence of any informational content. We examine the trading symbols of US firms and find that stocks with clever tickers (those that are actual words in the English language) are more liquid, as measured by higher turnover and trading volume, as well as lower spreads. Furthermore, clever ticker stocks are traded more by uninformed investors and have larger market reactions on earnings announcement days. These results suggest that ticker fluency facilitates trading by improving the firm's visibility among retail investors through attention grabbing and memorization.     

Intraweek and intraday trade patterns and dynamics

This paper investigates informed traders' order-splitting strategies on different days of the week and times of the day for a sample of stocks traded on the Australian Stock Exchange. Based on cumulative price changes, we document that informed traders tend to use medium size trades. We find that informed investors concentrate their strategic trading on Mondays and particularly during the first trading hour. In addition, informed investors also use large size trades around market opening and closing, as well as on days other than Mondays and Fridays. These results are more pronounced for the large market capitalization stocks.     

TIME-VARYING FACTORS AND CROSS-AUTOCORRELATIONS IN SHORT-HORIZON STOCK RETURNS

In this paper I show that the lead-lag pattern between large and small market value portfolio returns is consistent with differential variations in their expected return components. I find that the larger predictability of returns on the portfolio of small stocks may be due to a higher exposure of these firms to persistent (time-varying) latent factors. Additional evidence suggests that the asymmetric predictability cannot be fully explained by lagged price adjustments to common factor shocks: (i) lagged returns on large stocks do not have a strong causal effect on returns on small stocks; (ii) trading volume is positively related to own- and cross-autocorrelations in weekly portfolio returns; and (iii) significant cross-autocorrelation exists between current returns on large stocks and lagged returns on small stocks when trading volume is high.     

Portfolio risk,adjustment costs,and security dealers' bid/ask spreads

This article notes that dealers' bid/ask spreads should vary directly with their costs of adjusting to inventory imbalances. Thus, well-diversified dealers are expected to quote lower bid/ask spreads on stocks with substantial total risk caused by undiversifiable risk. Furthermore, the effect of systematic risk on bid/ask spreads should be negligible if dealers are compensated for systematic risk by market returns. This article shows that, empirically, bid/ask spreads of OTC stocks are insensitive to the systematic risk of individual stocks—even when only stocks with stable betas are considered. Furthermore, bid/ask spreads are not sensitive to changes in market variance, as would be expected if systematic risk affected spreads. While unsystematic risk affects bid/ask spreads, its effect is pronounced for stocks traded by small, undiversified dealers. If stocks are only traded by large dealers with low diversification costs, unsystematic risk does not affect bid/ask spreads.     

Sell on the news: Differences of opinion,short-sales constraints,and returns around earnings announcements

Miller [1977. Risk, uncertainty, and divergence of opinion. Journal of Finance 32, 1151–1168] hypothesizes that prices of stocks subject to high differences of opinion and short-sales constraints are biased upward. We expect earnings announcements to reduce differences of opinion among investors, and consequently, these announcements should reduce overvaluation. Using five distinct proxies for differences of opinion, we find that high differences of opinion stocks earn significantly lower returns around earnings announcements than low differences of opinion stocks. In addition, the returns on high differences of opinion stocks are more negative within the subsample of stocks that are most difficult for investors to sell short. These results are robust when we control for the size effect and the market-to-book effect and when we examine alternative explanations such as financial leverage, earnings announcement premium, post-earnings announcement drift, return momentum, and potential biases in analysts’ forecasts. Also consistent with Miller's theory, we find that stocks subject to high differences of opinion and more binding short-sales constraints have a price run-up just prior to earnings announcements that is followed by an even larger decline after the announcements.     

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。     

Opening price manipulation and its value influences

We investigate how opening price manipulation influences market behaviors and investors' returns. Analyzing direct evidence comprising 87 opening price manipulation cases, and indirect evidence consisting of 19,003 suspected cases detected by an opening price manipulation identification model that we construct, we examine the impact of manipulation on mispricing, investors' welfare, trading activity and price volatility. Our results indicate that manipulated stocks experience significantly lower returns and a higher probability of price reversal after manipulation. Investors who purchase manipulated stocks at their opening price, or the volume-weighted average price, on the manipulation day make losses on their investments. Further, manipulation increases market trading activity and price volatility due to the influx of retail investors. Our additional analysis demonstrates that enhancing the intensity of external supervision and internal governance can mitigate mispricing caused by opening price manipulation. Our study provides novel evidence of the economic consequences of open market manipulation and policy implications for governments and regulators to develop effective supervisory processes to reduce manipulation and mitigate its impact on efficient markets.     

Individual Investors and Volatility

We show that retail trading activity has a positive effect on the volatility of stock returns, which suggests that retail investors behave as noise traders. To identify this effect, we use a reform of the French stock market that raises the relative cost of speculative trading for retail investors. The daily return volatility of the stocks affected by the reform falls by 20 basis points (a quarter of the sample standard deviation of the return volatility) relative to other stocks. For affected stocks, we also find a significant decrease in the magnitude of return reversals and the price impact of trades.     

Stock Returns in Thinly Traded Markets

We examine the share price behavior of thinly traded NASDAQ National Market System stocks during periods when financial markets are open but the individual stocks do not trade. The absence of trade allows us to isolate the effect of nontrading from that of market closure. We find that nontrading stocks have negative mean returns and lower variances regardless of whether markets are open or closed. Two-day returns that include one nontrading day have a mean daily return of -0.226% compared to +0.164% for two-day returns over consecutive trading days. Two-day returns that include one nontrading day have only 3.8% higher variance than one-day returns. We conclude that the relation between transaction arrival, mean returns, and volatility depends on whether a stock is trading and not simply on whether the market is open.