• Asia-Pacific Journal of Business
• /
• v.14 no.3
• /
• pp.45-66
• /
• 2023

Purpose - This paper examines whether overnight returns and idiosyncratic volatility (IVOL) jointly affects the cross-section of expected stock returns in the Korean stock market. Design/methodology/approach - Constructing 5×5 bivariate monthly portfolios independently sorted on overnight returns and IVOL, this paper tests whether overpricing of stocks with high overnight returns is more pronounced for the stocks that also have high IVOL. In addition, we also investigate whether time-variation in the degree of overpricing for those stocks can be explained by market volatility. Findings - Our results show that stocks having both high overnight returns and high IVOL exhibit strong negative returns in the future. In contrast, we are unable to observe such negative returns for the stocks that have high overnight returns and low IVOL. This suggests that overpricing of stocks with high overnight returns is concentrated for the stocks having high IVOL. Moreover, we also find that the degree to which such stocks are overpriced is negatively related to market volatility. Research implications or Originality - his paper is the first attempt to explore whether degree of overpricing of stocks having high overnight returns is related to IVOL. We also discover time-varying property of overpricing is jointly driven by overnight returns and IVOL. Our results indicate that IVOL might help explain other previously documented stock return anomalies, suggesting interesting topics for future research.

• Asia-Pacific Journal of Business
• /
• v.11 no.4
• /
• pp.243-254
• /
• 2020

Purpose - This paper explores whether overnight returns measured from the last closing price to today's opening price explain the cross-section of stock returns. Design/methodology/approach - This study is conducted using the Korean stock market data from 1998 to 2018, obtained from DataGuide database. The analysis begins with portfolio-level tests, followed by firm-level cross-sectional regressions. Findings - First, when decile portfolios sorted on the daily average of overnight returns in the previous months, the highest decile portfolio exhibits a significant negative risk-adjusted return. This suggests that stocks with higher average overnight returns are temporarily overvalued due to buying pressure from investors. Second, at least 6 months of persistence exists in average overnight returns, which is in line with the results reported by Barber, Odean and Zhu (2009) that investor sentiment persists over several weeks. Finally, Fama-MacBeth cross-sectional regression of expected returns after controlling for a variety of firm characteristic variables such as firm size, book-to-market ratio, market beta, momentum, liquidity, short-term reversal, the slope coefficient for overnight returns remains negative and statistically significant. Research implications or Originality - Overall, the evidence consistently suggests that overnight return is considered as a new priced factor in the cross-section of expected returns. The findings of this paper not only adds to finance literature, but also could be useful to practitioners in making stock investment decision.

• The Korean Journal of Financial Management
• /
• v.27 no.2
• /
• pp.145-167
• /
• 2010

We investigate the dynamic relationship between stock returns and investors' behavior. For the putpose of the paper, daily KOSPI returns are decomposed into two parts: overnight returns and daytime returns. Overnight return is measured by the closing price of the previous day and the opening price of the current day. And daytime return is measured by the opening and closing prices of the current day. Qvernight returns are assumed to reflect global economic information, and daytime returns, domestic or local information. Major results are as follows: Foreign investors' behavior has an effect on the overnight returns more than the daytime returns. Individual investors' behavior, however, has little effect on the overnight returns, but not the daytime returns. Consequently, forecast error variance decomposition shows that the variance explanation power of foreign investors is higher in overnight returns rather than in the daytime returns. And the variance explanation power of individual investors is higher in daytime returns rather than in overnight returns. It implies that foreign investors employ dynamic hedging strategies and give more weight to global economic information rather than to domestic information. We conclude that investment behavior of foreign investors and domestic individuals is based on different economic information. This paper's findings are consistent with the economic situation that the Korean capital markets have faced since the global financial crisis of August 2008.

• Journal of Information Technology Applications and Management
• /
• v.17 no.3
• /
• pp.151-162
• /
• 2010

Recent developments in financial market liberalization and information technology are accelerating the interdependence of national stock markets. This study explores the information spillover effect of the US stock market on the overnight and daytime returns of the Korean stock market. We develop a profitable intra-day trading strategy based on the information spillover effect. Our study provides several important conclusions. First, an information spillover effect still exists from the overnight US stock market to the current Korean stock market. Second, Korean investors overreact to both good and bad news overnight from the US. Therefore, there are significant price reversals in the KOSPI 200 index futures prices from market open to market close. Third, the overreaction effect is different between weekdays and weekends. Finally, the suggested intra-day trading system based on the documented overreaction hypothesis is profitable.

• The Korean Journal of Applied Statistics
• /
• v.29 no.1
• /
• pp.85-98
• /
• 2016

This study makes an empirical comparison of various realized volatilities (RVs) in terms of overnight returns. In financial asset markets, during overnight or holidays, no or few trading data are available causing a difficulty in computing RVs for a whole span of a day. A review will be made on several RVs reflecting overnight return variations. The comparison is made for forecast accuracies of several RVs for some financial assets: the US S&P500 index, the US NASDAQ index, the KOSPI (Korean Stock Price Index), and the foreign exchange rate of the Korea won relative to the US dollar. The RV of a day is compared with the square of the next day log-return, which is a proxy for the integrated volatility of the day. The comparison is made by investigating the Mean Absolute Error (MAE) and the Root Mean Square Error (RMSE). Statistical inference of MAE and RMSE is made by applying the model confidence set (MCS) approach and the Diebold-Mariano test. For the three index data, a specific RV emerges as the best one, which addresses overnight return variations by inflating daytime RV.

• The Korean Journal of Financial Management
• /
• v.20 no.1
• /
• pp.163-190
• /
• 2003

This study tests the hypothesis of market efficiency through the information spillover effects over price and volatility across countries by using open-to-close(daytime) returns and close-to-open(overnight) returns of NASDAQ, KOSDAQ and JASDAQ data from January 3, 1997 to December 21, 2000. Based on Granger-causality and time-varying AR(1)-GARCH(1, 1)-M models we document that the evidence of statistically significant conditional mean and volatility spillovers effects from the daytime returns and volatility of NASDAQ to the overnight returns and volatility of KOSDAQ is observed both before and after the IMF foreign currency crisis but not to the close-to-open return before the IMF foreign currency crisis. We can understand the information spillover effect from NASDAQ to KOSDAQ on the overnight rather than the daytime grows more significantly after the IMF foreign currency crisis. We also find the interactive information spillover effect between NASDAQ and JASDAQ both before and after the IMF financial crisis, in particular, to close-to-open return. In addition, the market efficiency between KOSDAQ and NASDAQ is on an increasing trend through IMF foreign currency crisis.

• The Korean Journal of Financial Management
• /
• v.15 no.1
• /
• pp.73-94
• /
• 1998

This paper contributes to the ongoing controversy over price and volatility spillovers across countries by providing new evidence with the futures data of the S&P 500 and Nikkei 225 index futures contacts from January 3, 1990 to April 16, 1996. Based on the two-stage symmetric and asymmetric GARCH models we document that both the U.S. and the Japanese daytime returns significantly influence the subsequent overnight returns of the other market. We find no signs of volatility spillovers between two international markets with the symmetric model. However, with the asymmetric models, we find that the magnitude of foreign negative shocks are different from the positive ones. The findings generally suggest that the two markets are more sensitive to the bad news originating in the other market. This nature of transmission between two markets would have important implications to the arbitragers who are trying to exploit the short-term dynamics of price and volatility movements across two security markets.

• The Korean Journal of Financial Studies
• /
• v.2 no.2
• /
• pp.221-256
• /
• 1995

This paper compares the intra-day patterns on the NYSE and AMEX of volatility, trading volume and bid-ask spreads for European and Japanese dually-listed stocks with American stocks of comparable average trading volume and volatility. It is shown that the intra-day patterns for these stocks are remarkably similar even though public information flows differ markedly across these stocks during the trading day. In the early morning, all stocks have higher volatility than later in the day, but this phenomenon is most pronounced for Japanese stocks and affects American stocks the least. We argue that these patterns are consistent with markets reacting to the overnight accumulation of public information but are inconsistent with the view that early morning volatility can be attributed to monopolistic specialist behavior.

• The Korean Journal of Financial Management
• /
• v.23 no.2
• /
• pp.171-187
• /
• 2006

This paper investigates the pricing information transmission between NYSE listed Chinese ADRs and their underlying shares by using GJR. The data in this study consist of daytime and overnight returns on 7 chinese stocks End their ADRs on the NYSE for the period from December 2002 to december 2005. We have round that the home market leadership hypothesis can be applied to the Chinese stocks. We have also found that return spillover effect is stronger than volatility spillover effect.

• Management & Information Systems Review
• /
• v.31 no.4
• /
• pp.593-609
• /
• 2012

This study is designed to investigate whether the information spillover effect is existed between the foreign investors' unexpected volatility of net purchasing intensity and the volatilities of returns in terms of daily closing stock return, overnight return, and daytime return, before and after financial crisis in Korea. The result of this study shows that there is negative information spillover effect between the foreign investors' unexpected volatility of net purchasing intensity and the volatility of daily closing stock return for time t-1. However, there is an opposite result for time t, showing positive information transmission effect. For the overnight return, the test result provides there is no statistical significance between the foreign investor's unexpected volatility of net purchasing intensity and the volatilities of return. In addition, I found that the information transmission effect is existed between the foreign investor's unexpected volatility of net purchasing intensity and the volatilities of the daytime return for the entire timeline.