The Reversal of the Monday Effect: New Evidence from US Equity Markets

This article re-examines the Monday effect in the US stock market from 1964–1999 using daily returns from three large-cap indexes and two small-cap indexes. In the period before 1987, Monday returns are significantly negative in all five US stock indexes, confirming previous empirical findings. In the post-1987 period, we uncover a significant reversal of the Monday effect in the large-cap indexes (NYSE, S&38;P500 and DJCOMP), since Monday returns are significantly positive. Furthermore, significant differences in the persistence and reversal of the Monday effect are found between large-cap and small-cap stock indexes.     

The Monday effect revisited: An alternative testing approach

This paper questions traditional approaches for testing the Monday effect of stock returns. We propose an alternative, multiple hypothesis testing approach based on the closure test principle which controls the multiple type I error. We consider the US, the UK and the German stock markets and test Monday related pairwise comparisons of daily expected stock returns, while the probability of committing any type I error is always kept smaller than a prespecified level α, for each combination of true null hypotheses. Overall, the new testing approach supports previous findings of a Monday effect for the 1970s and 1980s, in particular for the US and Germany, while it suggests that the Monday effect has vanished in the 1990s and 2000s in all three markets. The comparison of the closure test procedure, the traditional multiple t-test and the Bonferroni test, a classical multiple test procedure, shows that traditional testing may result in spurious significance while the Bonferroni test may sometimes be too conservative.     

Explaining Monday Returns

The Monday effect is reexamined using two stock indexes and a sample of 452 individual stocks that trade on the London Stock Exchange. The results based on conventional test methods reveal a negative average return on Monday. Extending the analysis to examine the effects of various possible influences simultaneously, the average Monday return becomes positive and does not differ significantly from the average returns of most other days of the week. Fortnight, ex‐dividend day, account period, (bad) news flow, trading activity, and bid‐ask spread effects are all controlled for. The results broadly support the trading time hypothesis.     

The Weekend Effect, 'Reverse' Weekend Effect, and Firm Size

In this paper, we find a 'reverse%rsquo; weekend effect — whereby returns for Monday are positive and significantly greater than returns for the preceding Friday — in recent data for major stock indexes. We also find that, while a weak weekend effect exists in portfolios of smaller firms, the effect begins to diminish and weak 'reverse' weekend effect begins to appear in medium size firms. The 'reverse' weekend effect becomes strong and statistically significant in portfolios of large firms. The detection of a 'reverse' weekend effect in portfolios of large firms is a new finding in the literature.     

A New Look at the Monday Effect

It is well documented that expected stock returns vary with the day-of-the-week (the Monday or weekend effect). In this article we show that the well-known Monday effect occurs primarily in the last two weeks (fourth and fifth weeks) of the month. In addition, the mean Monday return of the first three weeks of the month is not significantly different from zero. This result holds for most of the subperiods during the 1962–1993 sampling period and for various stock return indexes. The monthly effect reported by Ariel (1987) and Lakonishok and Smidt (1988) cannot fully explain this phenomenon.     

The wandering weekday effect in major stock markets

This paper reports a wandering weekday effect: the pattern of day seasonality in stock market returns is not fixed, as assumed in the Monday or weekend effects, but changes over time. Analysing daily closing prices in eleven major stock markets during 1993–2007, our results show that the wandering weekday is not conditional on average returns in the previous week (the “twist” in the Monday effect). Nor does it diminish through the period of analysis. The results have important implications for market efficiency, and help to reconcile mixed findings in previous studies, including the reported disappearance of the weekday effect in recent years.     

Asymmetric volatility spillover between oil-importing and oil-exporting countries' economic policy uncertainty and China's energy sector

While the relationship between economic policy uncertainty(EPU) and energy market is of great interest to economist, previous research dose not differentiate the effect from oil-importing countries to oil-exporting countries' EPU on the a country's energy sector. In this paper, we address this issue by testing the effect of importer and exporter's EPU on the largest oil-importing country, China, as oil-importing affected greatly by the economic policy. TVP-FAVAR model is applied to obtain the factors and time-varying coefficients of 21 countries' EPU monthly indexes and energy stock realized volatility. We find that the Chinese energy sector's stock volatility is positively related to EPU shocks and that bad volatility has a stronger impact than good volatility. Second, the volatility spillover from oil-exporting countries' EPU on the Chinese energy sector is stronger than that from oil-importing countries' EPU, with a stronger effect for bad volatility than for good volatility. Finally, The bad volatility spillover and spillover asymmetry is stronger during the crisis periods, such as the debt crisis, energy contention, oil price turbulence, or limited production agreement, both symmetric and asymmetric spillovers increase. Our findings have potentially important implications for the regulators and investors on Chinese oil market with different types of countries' EPU.     

The Weekly Pattern in Stock Returns: Cash versus Futures: A Note

This paper presents tests designed to determine whether the weekly pattern in stock returns continues after the introduction of futures trading on stock indexes and whether the pattern carries over to the futures market. Using data for the SP500, I find that the “Monday effect” does persist in the cash market, but there is no evidence of a similar pattern in the futures market.     

INTERNATIONAL EVIDENCE ON WEEKEND ANOMALIES

Recent studies on the U.S. market find that the Monday effect is observed mainly when the return on the previous Friday is negative or when the Monday falls within the last two weeks of the month. I look for international evidence and examine whether such properties of the Monday effect are related to another anomalous phenomenon—high weekend correlation. By examining twenty‐three equity market indexes, I find that the negative Friday is, in general, important to the Monday effect. Furthermore, Monday returns tend to be lowest on the fourth week of the month. Although high weekend correlation is also common to these markets, it seems not related to the bad‐Friday factor and shows no seasonality across weeks of the month. JEL classification: G15, G10.     

CEO Stock Options and Equity Risk Incentives

Abstract:   We test the hypothesis that the risk incentive effects of CEO stock option grants motivate managers to take on more risk than they would otherwise. Using a sample of mergers we document that the ratio of post‐ to pre‐merger stock return variance is positively related to the risk incentive effect of CEO stock option compensation but this relationship is conditioned on firm size, with firm size having a moderating effect on the risk incentive effect of stock options. Using a broader time‐series cross‐sectional sample of firms we find a strong positive relationship between CEO risk incentive embedded in the stock options and subsequent equity return volatility. As in the case of the merger sample, this relationship is stronger for smaller firms.     

On a Non-linear Risk Analysis for Stock Market Indexes

We propose a method to detect early signs of a potential major crash in the market from only the information of the time series representing its stock market data. As reinforcement of the abnormality test Test(ABN) developed in Okabe, Matsuura, and Klimek (International Journal of Pure and Applied Mathematics, 3, 443–484, 2002), we introduce in this paper a risk graph to measure abnormality of time series by using the non-linear prediction analysis in the theory of KM₂O-Langevin equations. By applying it to real data of stock market indexes on the Black Monday of 1987 and those during the past 7 years from January 2000 to December 2006, we investigate whether we can detect early signs of a potential major crash in the market by watching the behavior of the risk graph. An erratum to this article can be found at     

Privatization,political risk and stock market development in emerging economies

This paper investigates whether privatization in emerging economies has a significant indirect effect on local stock market development through the resolution of political risk. We argue that a sustained privatization program represents a major political test that gradually resolves uncertainty over political commitment to a market-oriented policy as well as to regulatory and private property rights. We present evidence suggesting that progress in privatization is indeed correlated with improvements in perceived political risk. Our analysis further shows that changes in political risk in general tend to have a strong effect on local stock market development and excess returns in emerging economies. We conclude that the resolution of political risk resulting from successful privatization has been an important source for the rapid growth of stock markets in emerging economies.     

GOOD NEWS, BAD NEWS, VOLUME, AND THE MONDAY EFFECT

New evidence is presented on the nature of the Monday effect in stock market returns. Using stock returns for the years 1962-1986, the Monday effect is found to be confined to periods of negative market returns. Monday's returns are no different from other weekday returns in periods of positive returns. In addition, trading volume and the Monday effect are related. Monday's volume is lower than the other weekdays. When returns are compared controlling for trading volume, we find that the Monday effect is confined to negative return periods with above normal volume, which represent only two per cent of the sample period.     

New Findings Regarding Day-of-the-Week Returns over Trading and Non-Trading Periods: A Note

This paper decomposes daily close to close returns into trading day and non-trading day returns. We discover that all of the average negative returns from Friday close to Monday close documented in the literature for stock market indexes occurs during the non-trading period from Friday close to Monday open. In addition, average trading day returns (open to close) are identical for all days of the week. January/firm size/turn-of-the-year anomalies are shown to be interrelated with day-of-the-week returns.     

An Intraweek Seasonality in the Implied Volatilities of Individual and Index Options

This paper studies intraweek seasonalities in the implied volatilities of options on stock market indices. Oneway analysis of variance isolates the daily behavior of implied volatilities. The differential between call implied volatility and put implied volatility tends to drop on Friday and rise on Monday. Relying on a synthetic futures contract created from options, an explanatory model is proposed. The model complements previous research on the difference between the intraweek behavior of stock market indices and that of derivative instruments based on the indices.     

The Differential Effects of Noneconomic Damage Cap Levels on Medical Malpractice Insurers

This study examines the effect of tort reform on medical malpractice insurers with an emphasis on the effect of cap levels on noneconomic damages. While previous research finds that caps on noneconomic damages have a beneficial effect on insurer performance, these studies do not evaluate the effects of caps of varying size. Examining insurer data from 1997 to 2007, we test whether cap levels matter. We find that insurer performance generally improves when the cap is set at $250,000, but caps exceeding $250,000 are not associated with improved performance, as they are possibly not binding on award amounts.     

不同股市行情下的星期效应研究——基于沪深股市的实证检验

本文基于我国股票市场中一波最长的熊市和牛市行情,运用GARCH模型研究不同行情下的星期效应。研究发现,整个样本区间内星期效应并不显著,但在熊市和牛市子样本中却分别存在明显的星期效应,具体表现：熊市行情下,最高收益率出现在周二,最低收益率出现在周一;牛市行情下,最高收益率出现在周一,最低收益率出现在周四,且结论具有显著性。因此,按行情对股票市场进行星期效应研究,可有效克服总体样本所得结论的模糊性。     

Weekend Effect, 'Reverse' Weekend Effect, and Investor Trading Activities

Abstract:   In this study, we document evidence of a 'reverse' weekend effect – whereby Monday returns are significantly positive and they are higher than the returns on other days of the week – over an extended period of eleven years (from 1988 to 1998). We also find that the 'traditional' weekend effect and the 'reverse' effect are related to firm size in that the 'traditional' weekend effect tends to be associated with small firms while the 'reverse' weekend effect tends to be associated with large firms. In addition, we find that during the period in which the 'reverse' weekend effect is observed, Monday returns for large firms tend to follow previous Friday returns when previous Friday returns are positive , but they do not follow the previous Friday returns when Friday returns are negative . Furthermore, we find that during the period in which the 'reverse' weekend effect is observed, Monday returns are positively related to the volume of medium‐size and block transactions, but negatively related to the volume of odd‐lot transactions.     

Stock prices, news, and business conditions

Previous research finds that fundamental macroeconomic newshas little effect on stock prices. We show that after allowingfor different stages of the business cycle, a stronger relationshipbetween stock prices and news is evident. In addition to stockprices, we examine the effect of real activity news on proxiesfor expected cashflows and equity discount rates. We find thatwhen the economy is strong the stock market responds negativelyto news about bigger real economic activity. This negative relationis caused by the larger increase in discount rates relativeto expected cashflows.     

Identifying multiple outliers in heavy-tailed distributions with an application to market crashes

Heavy-tailed distributions, such as the distribution of stock returns, are prone to generate large values. This renders difficult the detection of outliers. We propose a new outward testing procedure to identify multiple outliers in these distributions. A major virtue of the test is its simplicity. The performance of the test is investigated in several simulation studies. As a substantive empirical contribution we apply the test to Dow Jones Industrial Average return data and find that the Black Monday market crash was not a structurally unusual event.