Are stock markets really so inefficient? The case of the “Halloween Indicator”

The old and simple investment strategy “Sell in May and Go Away” (also referred to as the “Halloween effect”) enjoys an unbroken popularity. Recent studies suggest that the Halloween effect even strengthened rather than weakened since its first publication by Bouman and Jacobsen (2002). We implement regression models as well as Hansen’s (2005) “Superior Predictive Ability” test to analyze whether stock markets are really so inefficient. In line with the predictions of market efficiency, our results reject the hypothesis that a trading strategy based on the Halloween effect significantly outperforms.     

Is it the weather?

We show that results in the recent strand of the literature, which tries to explain stock returns by weather induced mood shifts of investors, might be data-driven inference. More specifically, we consider two recent studies [Kamstra, Mark J., Kramer, Lisa A., Levi, Maurice D., 2003a. Winter blues: A SAD stock market cycle. American Economic Review 93(1), 324–343; Cao, Melanie, Wei, Jason, 2005. Stock market returns: A note on temperature anomaly. Journal of Banking and Finance 29(6), 1559–1573] that claim that a seasonal anomaly in stock returns is caused by mood changes of investors due to lack of daylight and temperature variations, respectively. While we confirm earlier results in the literature that there is indeed a strong seasonal effect in stock returns in many countries: stock market returns tend to be significantly lower during summer and fall months than during winter and spring months as documented by Bouman and Jacobsen [Bouman, Sven, Jacobsen, Ben, 2002. The Halloween indicator, Sell in May and go away: Another puzzle. American Economic Review, 92(5), 1618–1635], there is little evidence in favor of a SAD or temperature explanation. In fact, we find that a simple winter/summer dummy best describes this seasonality. Our results suggest that without any further evidence the correlation between weather-related variables and stock returns might be spurious and the conclusion that weather affects stock returns through mood changes of investors is premature.     

Online Search Frequency,Retail Investor Overreaction,and the Cross-Section of Stock Returns: Evidence from the Chinese Stock Market

I find a strong negative relation between online search frequency and future returns on the Chinese stock market. I suggest that this effect captures retail investor overreaction to unexpected signals, because online search frequency reflects the efforts made by investors to obtain firm-specific knowledge. The effect is particularly strong in stocks with high information uncertainty (high analyst dispersion, big past earnings surprises, low analyst coverage, and large trading volume), whose intrinsic values are difficult or costly for investors to estimate. Online search frequency as a direct indicator of retail investors’ reaction to signals also sheds light on the idiosyncratic volatility (IVOL) puzzle. I find that this puzzle is more pronounced in high-search-frequency subsamples and disappears in low-search-frequency subsamples. Further evidence shows that high search frequency strengthens the negative IVOL effect in stocks with positive signals but weakens this effect in stocks with negative signals. I suggest that the IVOL puzzle in the Chinese market can be partially explained as a reversal following overreaction to positive signals by retail investors.     

A Tale of Two Anomalies: Higher Returns of Low‐Risk Stocks and Return Seasonality

Prior studies have shown that low beta and low volatility stocks earn higher average returns than high beta and high volatility stocks, contradicting the prediction of the capital asset pricing model and the fundamental relationship between risk and return. In this paper, we demonstrate that this phenomenon is driven by the seasonality of stock returns. We show that the risk‐return tradeoff does hold in the nonsummer months, and that switching to a portfolio of low‐risk stocks in summer outperforms—both in terms of absolute and in risk‐adjusted returns—buy and hold strategies as well as the Sell in May strategy of switching to treasury bills in summer.     

Jensen's alpha and the market‐timing puzzle

Theory predicts that market‐timing activities bias Jensen's alpha (JA). However, empirical studies have failed to find consistent evidence of this bias. We tackle this puzzle in a nested model analysis and show that the bias contains an exogenous market component that is unrelated to market‐timing skill. In a comprehensive empirical analysis of US mutual funds, we find that the timing‐induced bias in JA is mainly driven by this market component, which is uncorrelated with measured timing activities. Measures of total performance that allow for timing activities are virtually identical to JA, even if timing activities are present in the evaluated fund. Hence, we conclude that JA is a sufficient measure of total performance.     

THE IMPACT OF MARKET MAKER CONCENTRATION ON ADVERSE‐SELECTION COSTS FOR NASDAQ STOCKS

We examine the impact of market maker concentration on adverse‐selection costs for NASDAQ stocks and find that more market makers results in lower costs. Furthermore, this reduction in adverse selection exceeds the overall reduction in spreads that is attributable to market maker competition. We hypothesize that order flow internalization is increasing in market makers and allows for greater information production, and is an explanation for our findings. Our results provide an explanation for the puzzle documented by previous work that finds that adverse‐selection costs for NASDAQ tend to be lower than for the New York Stock Exchange, whereas spreads tend to be higher.     

基于上证50ETF期权的“定价核之谜”研究

基于上证50E T F和上证50E TF期权数据,本文经验研究了中国市场是否存在“定价核之谜”,并对“定价核之谜”与市场走势之间的关系进行了探讨。实证结果显示,中国市场存在“定价核之谜”,且“定价核之谜”与下期市场收益率呈显著负向关系、与下期市场振幅呈显著正向关系。本文首次给出了“定价核之谜”在中国金融市场存在的经验证据,并且证实了“定价核之谜”对下期市场走势具有一定的预测作用。     

The forward discount puzzle and market efficiency

We argue that the forward discount puzzle is primarily a statistical phenomenon and that statistical rejections of Uncovered Interest Parity do not necessarily constitute valid rejections of market efficiency. We find by using a Taylor expansion a theoretical negative bias in existing regressions of UIP. We propose two alternative tests for market efficiency, one of which is designed to measure the degree of market inefficiency. Our results from these tests indicate that for all four of the bilateral dollar parities studied the foreign exchange market is efficient despite decisive clear rejections of UIP using the conventional regression approach.     

Can Stock Recommendations Predict Earnings Management and Analysts’ Earnings Forecast Errors?

In this article we present evidence that a firm's stock price sensitivity to earnings news, as measured by outstanding stock recommendation, affects its incentives to manage earnings and, in turn, affects analysts' ex post forecast errors. In particular, we find a tendency for firms rated a Sell (Buy) to engage more (less) frequently in extreme, income–decreasing earnings management, indicating that they have relatively stronger (weaker) incentives to create accounting reserves especially in the form of earnings baths than other firms. In contrast, firms rated a Buy (Sell) are more (less) likely to engage in earnings management that leaves reported earnings equal to or slightly higher than analysts' forecasts. Our empirical results provide direct evidence of purported, but heretofore, weakly documented equity market incentives for firms to manage earnings. They are also consistent with a growing body of literature that finds analysts either cannot anticipate or are not motivated to anticipate completely in their forecasts firms' efforts to manage earnings.     

New evidence on nominal exchange rate predictability

The Meese–Rogoff puzzle, one of the well-known puzzles in international economics, concerns the weak relationship between nominal exchange rates and market fundamentals. The purpose of this paper is to show that market fundamentals do in fact matter in forecasting nominal exchange rates. In particular, we emphasize the importance of the Harrod–Balassa–Samuelson effect in modeling deviations from purchasing power parity. Based on the post-Bretton Woods period, we provide solid out-of-sample evidence that rejects the random walk forecast model at medium-term and long-term forecast horizons. We also find mild evidence for out-of-sample predictability of nominal exchange rates over the short term.     

Why is timing perverse?

The existence of negative market timing, even for passive portfolios, poses a relevant puzzle when assessing portfolio management. In this paper, we develop a simple theoretical model so as to explain why such perverse market timing might occur and why those stocks with the lowest beta in upward markets exhibit pronounced negative timing. Our explanation is based on the existence of higher correlations of stocks in down markets than in up markets. We find that changes in beta, which drives timing, has four components; however, just two of these, mean covariance shift and covariances dispersion map, serve to explain the asymmetric behavior across stocks. We find that a high percentage of the negative market timing ability identified for mutual funds in the literature could be explained by this bias.     

Examining the bond premium puzzle with a DSGE model

The basic inability of standard theoretical models to generate a sufficiently large and variable nominal bond risk premium has been termed the “bond premium puzzle.” We show that the term premium on long-term bonds in the canonical dynamic stochastic general equilibrium (DSGE) model used in macroeconomics is far too small and stable relative to the data. We find that introducing long-memory habits in consumption as well as labor market frictions can help fit the term premium, but only by seriously distorting the DSGE model's ability to fit other macroeconomic variables, such as the real wage; therefore, the bond premium puzzle remains.     

New evidence on the announcement effect of convertible and exchangeable bonds

This study investigates the announcement and issuance effects of offering convertible bonds and exchangeable bonds using data for the Swiss and German markets during January 1996 and May 2003. The analysis suggests that announcement effects of convertible bonds and exchangeable bonds are associated with significantly negative abnormal returns. German firms exhibit a stronger reaction than Swiss firms, possibly for institutional reasons. We also investigate the effect of the market return of the announcement effect and find that the negative abnormal returns are significantly more pronounced when previous market returns have been negative. Furthermore, we analyze the relation between the announcement effects and equity components by controlling for the equity signal sent to the market. We find the size of the equity component of an issue to have a strong influence on the announcement effect for convertible but not for exchangeable securities and offer an explanation for this difference.     

Why do firms engage in selective hedging? Evidence from the gold mining industry

The widespread practice of managers speculating by incorporating their market views into firms’ hedging programs (“selective hedging”) remains a puzzle. Using a 10-year sample of North American gold mining firms, we find no evidence that selective hedging is more prevalent among firms that are believed to possess an information advantage. In contrast, we find strong evidence that selective hedging is more prevalent among financially constrained firms, suggesting that this practice is driven by asset substitution motives. We detect weak relationships between selective hedging and some corporate governance measures but find no evidence of a link between selective hedging and managerial compensation.     

Trusting the Stock Market

We study the effect that a general lack of trust can have on stock market participation. In deciding whether to buy stocks, investors factor in the risk of being cheated. The perception of this risk is a function of the objective characteristics of the stocks and the subjective characteristics of the investor. Less trusting individuals are less likely to buy stock and, conditional on buying stock, they will buy less. In Dutch and Italian micro data, as well as in cross‐country data, we find evidence consistent with lack of trust being an important factor in explaining the limited participation puzzle.     

Liquidity Premia and Transaction Costs

Standard literature concludes that transaction costs only have a second‐order effect on liquidity premia. We show that this conclusion depends crucially on the assumption of a constant investment opportunity set. In a regime‐switching model in which the investment opportunity set varies over time, we explicitly characterize the optimal consumption and investment strategy. In contrast to the standard literature, we find that transaction costs can have a first‐order effect on liquidity premia. However, with reasonably calibrated parameters, the presence of transaction costs still cannot fully explain the equity premium puzzle.     

Information diffusion and the predictability of New Zealand stock market returns

This paper examines the impact of international predictors from liquid markets on the predictability of excess returns in the New Zealand stock market using data from May 1992 to February 2011. We find that US stock market return and VIX contribute significantly to the out‐of‐sample forecasts at short horizons even after controlling for the effect of local predictors, while the contribution by Australian stock market return is not significant. We further demonstrate that the predictability of New Zealand stock market returns using US market predictors could be explained by the information diffusion between these two countries.     

市场摩擦对特质风险溢价的影响效应——基于A股主板市场的实证分析

与国外发达市场相比,我国A股主板市场的市场摩擦因素对市场微观结构和资产定价的影响更大。在防范和化解系统性风险的过程中,进一步分析市场摩擦如何作用于特质风险定价效应的问题具有重要的理论和现实意义。本文通过采用多维市场摩擦指标来代理信息不对称、交易成本、买卖限制、卖空限制、风险对冲和外部冲击,检验中国股市特质风险和预期收益率的关系,并判断出市场摩擦因素间的差异性影响机制。回归发现,市场摩擦和特质风险因子(特质波动率和特质偏度)都具有定价效应。各维度市场摩擦因素降低了股票流动性,进而增强了特质波动率的负向定价效应,部分解释了“特质波动率之谜”,但市场摩擦对特质偏度因子溢价的影响较为微弱。同时,基于特质波动率和特质偏度因子的投资策略能够产生超越CAPM、三因子和五因子模型的绝对收益,并印证了市场摩擦对特质风险因子绝对收益的影响作用。     

Marketability,control, and the pricing of block shares

Unlike in other countries, negotiated block shares have huge discounts in China. We argue that trading restrictions help to explain this puzzle. Block shares in China face trading restrictions in the open market and can only be traded in the form of block transfers at negotiated prices. Using a dataset of 233 block transfers in China between 2002 and 2003, we find that discounts on block share prices increase with the proportion of restricted shares in the ownership. The likelihood of private benefit of control has positive impact on block prices, but the effect diminishes when there are other large shareholders. Furthermore, private institutions offer a higher price than state-owned institutions.