Intraday price reversals in the US stock index futures market: A 15-year study

This paper gives a long-term assessment of intraday price reversals in the US stock index futures market following large price changes at the market open. We find highly significant intraday price reversals over a 15-year period (November 1987–September 2002) as well as significant intraday reversals in our yearly and day-of-the-week investigations. Moreover, the strength of the intraday overreaction phenomenon seems more pronounced following large positive price changes at the market open. That being said, the question of whether a trader can consistently profit from this information remains open as the significance of intraday price reversals is sharply reduced when gross trading results are adjusted by a bid–ask proxy for transactions costs.     

Intraday volatility in the stock index and stock index futures markets

We examine the intraday relationship between returns and returnsvolatility in the stock index and stock index futures markets.Our results indicate a strong intermarket dependence in thevolatility of the case and futures returns. Price innovationsthat originate in either the stock or futures markets can predictthe future volatility in the other market. We show that thisrelationship persists even during periods in which the dependencein the returns themselves appears to weaken. The findings arerobust to controlling for potential market frictions such asasynchronous trading in the stock index. Our results have implicationsfor understanding the pattern of information flows between thetwo markets.     

Voluntary disclosures and the exercise of CEO stock options

We examine voluntary disclosures around the exercise of CEO stock options. Previous research shows that managerial incentives depend on the intended disposition of the exercised options' underlying shares. When CEOs intend to sell the underlying shares of exercised options, they have an incentive to increase stock prices in the pre-exercise period. In contrast, when CEOs intend to hold the underlying shares, they have a tax incentive to decrease stock prices in the pre-exercise period. Consistent with these private incentives, we find a significant increase in the frequency and magnitude of good (bad) news announcements in the pre-exercise period when CEOs implement exercise-and-sell (exercise-and-hold) strategies. We provide some evidence that CEOs' propensities for opportunistic disclosures are positively related to the value of their exercised stock options. Lastly, we find that the Sarbanes–Oxley Act (SOX) generally reduces, but does not eliminate, this type of managerial opportunism.     

Intraday and interday volatility in the Japanese stock market

This paper characterizes the volatility in the Japanese stock market based on a 4-year sample of 5-min Nikkei 225 returns from 1994 through 1997. The intradaily volatility exhibits a doubly U-shaped pattern associated with the opening and closing of the separate morning and afternoon trading sessions on the Tokyo Stock Exchange. This feature is consistent with market microstructure theories that emphasize the role of private and asymmetric information in the price formation process. Meanwhile, readily identifiable Japanese macroeconomic news announcements explain little of the day-to-day variation in the volatility, confirming previous findings for US equity markets. Furthermore, by appropriately filtering out the strong intradaily periodic pattern, the high-frequency returns reveal the existence of important long-memory interdaily volatility dependencies. This supports recent results stressing the importance of exploiting high-frequency intraday asset prices in the study of long-run volatility properties of asset returns.     

Intraday volatility and periodicity in the Malaysian stock returns

Many empirical studies using high-frequency intraday data from a variety of markets indicate that PGARCH models give superior return volatility forecasts than those produced from standard GARCH models. This paper investigates into modelling approaches of four versions of PGARCH models of high-frequency data of Bursa Malaysia, in particular where the intraday volatility of double U-shaped pattern. It is examined through half-hourly dummy variables, quarterly-hourly dummy variables, Fourier Functional Form (FFF) based variables and spline-based variables. The non-periodic GARCH models, i.e., GARCH, EGARCH and TARCH are used for comparison of performance of best fit. The analysis show that among the four versions of PGARCH models, the half-dummy and the spline-based versions perform the best. EGARCH produced consistently superior results to other GARCH specifications.     

Price reversals versus price continuations: the transitory price effects of futures trading extension on the underlying stock market

This paper examines the transitory price effects of index futures trading extension on the underlying stock market. Based on the model formulation of George and Hwang (1995) and Amihud and Mendelson (1987) and using the Hong Kong data, we find that the extension of futures trading hour helps to reduce the opening pricing errors and change the correlations between daytime and overnight stock returns. Our finding adds to the literature that the trading behavior of derivatives has a significant influence on the transitory price changes of the underlying cash products.

Private and public disclosures and the efficiency of stock prices

In this paper I examine the effects of private and public disclosures on the informational efficiency of stock prices. In addition to making a public announcement such as an earnings announcement, a public firm can make private disclosure to an analyst. If the analyst's relative information advantage is below a threshold level, private disclosure to the analyst leads to more efficient stock price. I demonstrate that the allocation of information across market participants is an important determinant of price efficiency. While accounting regulators often argue the need for equal access to information, the paper shows that there are conditions under which a limited amount of informational inequality may lead to more efficient stock prices.     

Intraday risk management in International stock markets: A conditional EVT approach

The study compares the predictive ability of various models in estimating intraday Value-at-Risk (VaR) and Expected Shortfall (ES) using high frequency share price index data from sixteen different countries across the world for a period of seven and half months from September 20, 2013 to May 07, 2014. The main emphasis of the study has been given to Extreme Value Theory (EVT) and to evaluate how well Conditional EVT model performs in modeling tails of distributions and in estimating and forecasting intraday VaR and ES measures. We have followed McNeil and Frey's (2000) two stage approach called Conditional EVT to estimate dynamic intraday VaR and ES. We have compared the accuracy of Conditional EVT approach to intraday VaR and ES estimation with other competing models. The best performing model is found to be the Conditional EVT in estimating both the quantiles for the entire sample. The study is useful for market participants (such as intraday traders and market makers) involved in frequent intraday trading in such equity markets.     

The ex-dividend day stock price anomaly: evidence from the Greek stock market

This paper examines the ex-dividend stock price and trading volume behavior in the Greek stock market for the period 2000–2004. We use both standard event-study methodology and cross-sectional regression analysis in assessing the ex-dividend stock price anomaly. We find that stock prices drop less than the dividend amount. By examining abnormal returns as well as abnormal trading volume around the ex-dividend day, we find strong evidence of short-term trading, which is consistent with the presence of dividend-capturing activities around the ex-dividend day. The results from the cross-sectional regression analysis confirm that the short-term trading hypothesis explains the ex-dividend day stock price anomaly in Greece.

Insider stock pledging and stock price informativeness: Evidence from India

Insiders’ shares can act as collateral while raising funds from lenders. This study examines the impact of insiders’ stock pledging activities on stock price informativeness using a sample of 1835 Indian firms. Our findings report that insider stock pledging increases the informational efficiency of stock prices. This informational efficiency increases for larger firms with: (1) financial constraints (high leverage and low cash holdings); (2) greater reliance on trade credit; and (3) higher indulgence in related party transactions. We also provide evidence on abnormal share turnover as a trading mechanism through which insider stock pledging is related to stock price informativeness. Our findings are robust across different specifications and after accounting for endogeneity issues.     

Seasonalities in the German stock market

Financial Markets and Portfolio Management - This paper suggests innovative investment strategies drawing on return seasonalities. By means of an out-of-sample study of the German stock market, we...     

The ex-dividend day stock price behavior in the Chinese stock market

This paper analyzes the ex-dividend day stock price behavior in the Chinese stock market. This market allows to examine the impact of tax effects while keeping any microstructure factors constant. The findings from non-taxable stocks show that their price, on the ex-dividend day, falls by an amount that is not statistically different from the dividend. For the taxable sample, stock prices of small dividend yield stocks fall proportionally to the dividend paid. For the large dividend yield stocks, the price adjustment depends on the effective tax rate on dividend income. The overall findings are consistent with the tax hypothesis.     

The effects of oil price shocks on U.S. stock order flow imbalances and stock returns

This paper investigates for the first time the effects of oil demand shocks and oil supply shocks on stock order flow imbalances leading to changes in stock returns. Through the estimation of a structural VAR model, positive oil demand shocks are able to explain almost 36% of the observed variation in the daily average stock order flow imbalances measured by the buy/sell trades ratio; which consequently lead to a negative rather than positive stock returns reaction. In contrast, oil supply shocks exhibit a negative and marginally significant effect on stock order flow imbalances. Our aggregate analysis suggests that positive shocks on stock order flow imbalances are negatively related to stock returns. These effects are stronger for oil-related sectors when compared with the rest of the equities sectors.     

Asymmetric dynamics of stock price continuation

This paper finds that the dynamics of stock price continuation are asymmetrical, in terms of both business cycles and past performances. During times of recession, stock returns are explained differently for past losers and winners; the level of credit quality dominates the return dynamics for extreme losers, while levels of information-based trading activity and information ambiguity contribute to winners’ medium-term returns. Such asymmetry is proposed as the source of insignificant profits achieved using conventional momentum strategies. On the other hand, in times of expansion, conventional asset pricing factors are found to affect stock returns with a dependence on the level of credit quality; this suggests that more profitable momentum strategies remain to be discovered.     

Time-varying risk in the German stock market

This paper compares two specifications of the Capital Asset Pricing Model for a sample of German stocks. The specifications generate time-varying first and second moments by conditioning on past information. This explicit modelling of the time series behaviour of risk allows us to characterize the driving factors of variances and covariances of returns. In addition to a variety of diagnostic tests we evaluate the validity of the one-factor restriction in the CAPM. The main findings are that risk is time dependent and very variable and also that more than one factor is needed to fit the data set.     

The speed of stock price discovery

We develop closed-form expressions for the path and speed of stock price discovery in a utility-based CAPM with wealth effects. Two investors with uniquely bounded risk-preferences always apply opposite portfolio rebalancing trades. These trades determine the intra-period path and speed of price discovery in a Walrasian, tâtonnement setup. While conditions for maximum speed exist, convergence is rapid over a wide range of endowments and preferences. Convergence to equilibrium is exponential, and its speed depends on endowments, risk-preferences, firm size, and market price for risk. Convergence is not guaranteed, and the conditions for divergence are specified.     

Internationally cross-listed stock prices during overlapping trading hours: price discovery and exchange rate effects

We analyze exchange rates along with equity quotes for 3 German firms from New York (NYSE) and Frankfurt (XETRA) during overlapping trading hours to see where price discovery occurs and how stock prices adjust to an exchange rate shock. Findings include: (a) the exchange rate is exogenous with respect to the stock prices; (b) exchange rate innovations are more important in understanding the evolution of NYSE prices than XETRA prices; and (c) most (but not all) of the fundamental or random walk component of firm value is determined in Frankfurt.     

Messages in online stock forums and stock price synchronicity: Evidence from China

Online stock forums allow investors to share information and exchange opinions, which facilitates the incorporation of firm-specific information into prices and reduces stock price synchronicity. However, prior research presents mixed evidence as to the value of messages in online forums. Using the information of the Eastmoney Guba online forum in China, we find a causal and negative relation between Guba messages and stock price synchronicity. The finding is robust after accounting for media reports and firm fixed effects and using both an instrumental variable analysis and an experimental design that exploits exogenous changes in the authenticity of Guba messages. We find the impact of Guba information is attributed to its roles in both information dissemination and investor interaction and is more pronounced for messages with a negative narrative tone. Additional tests suggest Guba messages improve firm information disclosure quality, reduce stock price crash risk and decrease stock return volatility synchronicity.     

The impact of nominal stock price on ex-dividend price responses

In this paper, we examine whether nominal stock price can help to explain the ex-dividend day anomaly where stock prices drop by less than the dividend amount on the ex-dividend date. We find that stocks with lower nominal prices have ex-dividend day price drops that are more consistent with theoretical predictions based on an efficient market. After controlling for factors that have been previously documented to influence ex-dividend day stock price behavior, price-drop-to-dividend ratios are closer to one for lower priced stocks. To further explore this phenomenon, we examine the change in the price-drop-to-dividend ratio around stock splits. Firms that split their shares have a larger price-drop-to-dividend ratio after the split, and companies that reverse split their shares have a smaller price-drop-to-dividend ratio after the split. Our evidence indicates that ex-dividend day stock price behavior is influenced by the nominal price of a share and that this relation could also influence the decision to split a firm’s shares.