• Management & Information Systems Review
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• v.28 no.1
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• pp.25-44
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• 2009

This study examines long term performance of initial public offerings(IPO) after book building was introduced in KOSDAQ market. We use event time portfolio approach and calendar time portfolio approach to test if the performance of IPO is fair or not in long term. We estimate the performance by using the BHAR(buy and hold abnormal return), CAR(cumulative abnormal return), WR(wealth relatives) model in event time portfolio approach. And we calculate the performance by using Fama-French three factor model, CTAR(calendar time abnormal return), RATS(Return Across Time and Securities approach) model in calendar time portfolio approach. This study shows that the long term performance of IPO is positive with statistical significance as the results of the analysis through the various research method and all windows in all kinds of firms and total firms.

• Journal of Information Technology Services
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• v.17 no.1
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• pp.33-45
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• 2018

Recently, many South Korean firms have suffered financial losses and damaged corporate images from the data breaches. Accordingly, a firm should manage their IT assets securely through an information security investment. However, the difficulty of measuring the return on an information security investment is one of the critical obstacles for firms in making such investment decisions. There have been a number of studies on the effect of IT investment so far, but there are few researches on information security investment. In this paper, based on a sample of 76 investment announcements of firms whose stocks are publicly traded in the South Korea's stock market between 2001 and 2017, we examines the market reaction to information security investment by using event study methodology. The results of the main effects indicate that self-developed is significantly related to cumulative average abnormal returns (CAARs), while no significant effect was observed for discloser, investment characteristics and firm characteristics. In addition, we find that the market reacts more favorably to the news announced by the subject of investment than the vendor, in case of investments with commercial exploitation. One of main contributions in our study is that it has revealed the factors affecting the market reaction to announcement of information security investment. It is also expected that, in practice, corporate executives will be able to help make an information security investment decision.

• Journal of Korea Trade
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• v.24 no.6
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• pp.1-18
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• 2020

Purpose - This study investigates whether a listing effect exists in cross-border M&As and whether the effect can be attributed to the uncertainty of the GDP growth rate in the target firm's home country. We apply a joint variable analysis using M&A announcement data from the Korea Exchange (KRX), Shanghai Stock Exchange (SSE), and the Taiwan Stock Exchange (TWSE) from 2004 to 2013. We also conduct an event study using the measure of the uncertainty of the GDP growth rate (based on IMF statistics) in 55 target countries. Design/methodology - We measure the abnormal return (AR) using the market-adjusted model. We test the significance of the AR and the cumulative abnormal return (CAR) using a one-sample t-test. We examine the characteristics of the CARs depending on whether the target company is listed by applying a difference analysis using CAR as a test variable. In addition, we set CAR (-5, +5) as a dependent variable to identify the cause of the listing effect, and test both the financial characteristic variables of the acquirer and the collective characteristic variables of the merger as independent variables in the multiple regression analysis. Findings - First, we find the listing effect of cross-border M&As in the KRX, SSE, and TWSE, which represent the capital markets in Korea, China, and Taiwan, respectively. This listing effect persists during the global financial crisis and has a negative effect on the wealth of acquiring shareholders, especially when the target countries are emerging markets. Second, greater uncertainty regarding the target countries' economic growth in cross-border M&As has a negative effect on the wealth of acquiring firms' shareholders. Third, our empirical analysis demonstrates that the listing effect is attributable to the fact that firms listed in a target country with greater uncertainty of economic growth are more directly and greatly exposed to uncertain capital markets through stock markets, than are unlisted firms. Originality/value - This study is significant in that it presents a new strategic perspective in the study of cross-border M&As by demonstrating empirically that the listing effect is attributable to the uncertainty regarding the economic development of the target firms' home countries.

• Management & Information Systems Review
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• v.4
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• pp.327-348
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• 2000

There are three major motives for M&A, financial synergy effect, operating & managerial synergy effect, and tax effect. The purpose of this study is to prove the operating & managerial synergy effect of M&A. To do this, we analyze the market-ripple effect of M&A, focusing on the increase in market power. Specifically we use cross-sectional data from 1985 to 1998 to show whether a market power of mergers is higher than that of a matched non-merging control group. we use time series data to show whether a market power of merger is higher than that of pre-merger. Also we use the event study using market model to show the stock price movement after mergers. The result is that although revenue increase after mergers, profit of the firms does not improve after mergers. Also there is sufficient evidence to say that there is a cumulative abnormal return for the firms after mergers.

• Journal of the Korea Society of Computer and Information
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• v.21 no.1
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• pp.139-146
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• 2016

In this paper, we analyze the information asymmetry among investors in online trading environment using rumors which are collected in the Korean stock market for the eleven-year period between January 2004 and December 2014. We find that cumulative abnormal return of sample firms is negative and statistically significant, indicating that a significant fall of the stock price starts before the online disclosure, suggesting that the rumors were reflected in the stock price to a significant extent. Furthermore, individual investors show net purchases on firms prior to disclosure while institutional investors show net sales, showing that individual investors trade unfavorably vis-$\grave{a}$-vis institutional investors. This phenomenon is more evident for the KOSDAQ. This result confirms that the information asymmetry exists between individual and institutional investors in online trading environment.

• The Journal of Society for e-Business Studies
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• v.21 no.2
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• pp.81-96
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• 2016

This paper analyzes the impact of information breach on shareholder value by measuring the stock price reaction associated with the announcements of data breach. The breach firms in the sample lost, on average, 1.3% of their market value, amounting to 98.9 million won of loss within two-day of the event period after the announcement. We examine the abnormal returns in various categories (i.e., source, type, size, etc.) of information breach. Although the market does not react significantly to the announcements of outside breach, we find statistically significant market reactions to inside breach. We estimate abnormal returns over the following 60 days. The mean 60-day cumulative abnormal return and BHAR (buy-and-hold abnormal returns) are both significantly far from zero. We conclude that there is a coherent market reaction following the announcement. The difference between the market reactions to IT firms and Non-IT firms is statistically significant. But breach amount, firm size, and the year the breach occurred do not show to be significant variables.

• The Korean Journal of Financial Management
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• v.25 no.2
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• pp.191-213
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• 2008

This study tests and reconfirms the wealth transfer of mergers and acquisitions(M&As) by examining the changes in and the relationship between shareholder and bondholder wealth after the announcements of M&As for the publicly listed firms in Korea Stock Exchange and KOSDAQ market during $1999{\sim}2006$. The change in shareholder wealth is measured by the Cumulative Abnormal Return(CAR) at the M&A announcements, and the change in bondholder wealth is calculated using the Yield Spread Change(YSC) and the change in acquiring firms' credit ratings. The empirical tests show that the CAR of 344 sample acquiring firms at the announcement is 3.59%, which confirms results of the prior research on M&As in Korean market. The average YSC for 35 sample acquiring firms between $2001{\sim}2006$ proves to be negative when we use the yield spread of firms with comparable credit ratings as a benchmark, which means that the acquiring firms' bondholders gain with the announcements of M&As. We find the same result using another benchmark-the yield spread of government bonds. The improvement in the acquiring firms' credit ratings one year after the M&As also indicates that the M&As, on average, increase bondholder wealth. Our test results are consistent with those of the existing studies on the effect of bondholder wealth after the M&As in the United States, which shows that the bondholder wealth increases after the M&As. We do not find the evidence that there is a wealth transfer from the acquiring firms' bondholders to the shareholders after the M&A announcements. Rather, this study confirms that the wealth of the acquiring firms' bondholders increases in the M&As in Korea.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.6
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• pp.133-145
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• 2023

This paper examines whether investors have adapted to the venture capital(VC) investment style. VC firms invest in privately held companies and generate returns by selling them after the lock-up period expires. We analyze the impact on stock prices before and after the lock-up period expiration, and compare the Cumulative Abnormal Return(CAR) between the past period(2015-2017) and the recent period(2020-2022) to investigate the effect of the second venture boom. The main findings are as follows. First, unlike in the past, stock price returns around the lock-up period expiration have been lower than the KOSDAQ index in recent years. Second, the impact on stock prices is significant for both 1-month and 12-month lock-up periods. Specifically, it is confirmed that stocks held by venture capital and professional investors with a 1-month lock-up period respond in advance to their information after the second venture boom. Finally, we find that there is a difference in CAR depending on whether or not the company received VC investment after the second venture boom. Based on our findings, we suggest that VC firms need to revise their exit strategies to improve performance. This includes finding ways to reduce information asymmetry and fees, as well as developing strategies to mitigate market volatility. Additionally, the current lock-up period for VCs should be reconsidered as it may increase the risk of stock price decline. We recommend that the government revise the scope and duration of lock-up periods to protect investors after IPO.

• The Korean Journal of Financial Management
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• v.24 no.4
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• pp.201-232
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• 2007

In this study, we investigated public announcements of stock splits using the Korean Stock Market data from 2000 through 2007. The purposes of this study are to examine whether stock splits have the information contents in the Korean capital markets, and to investigate the possible cause of the market reactions. We measured the market reactions with abnormal returns, cumulative abnormal returns and cumulative average abnormal returns. For the purpose, two specific hypotheses were tested. One is 'Signalling Effects' where stock splits function as a signal through which managers transmit a favorable information for investors. The other is 'Liquidity Effects' where stock splits increase the trading convenience. We have th following results. Firstly, positive market effects were found when stock splits were announced. Secondly, there was difference in trading convenience between the high and the low split ratios. Finally, the long term performance through stock splits in the Korean capital markets was not significant.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.81-101
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• 2003

The financial statements purpose to provide useful information to decision-making process of business managers. The value-relevant information, however, embedded in the financial statement has been often overlooked in Korea. In fact, the financial statements in Korea have been utilized for nothing but account reports to Security Supervision Boards (SSB). The objective of this study is to develop earnings forecasting models through financial statement analysis using artificial intelligence (AI). AI methods are employed in forecasting earnings: artificial neural networks (ANN) for manufacturing industry and case~based reasoning (CBR) for banking industry. The experimental results using such AI methods are as follows. Using ANN for manufacturing industry records 63.2% of hit ratio for out-of-sample, which outperforms the logistic regression by around 4%. The experiment through CBR for banking industry shows 65.0% of hit ratio that beats the statistical method by 13.2% in holdout sample. Finally, the prediction results for manufacturing industry are validated through monitoring the shift in cumulative returns of portfolios based on the earning prediction. The portfolio with the firms whose earnings are predicted to increase is designated as best portfolio and the portfolio with the earnings-decreasing firms as worst portfolio. The difference between two portfolios is about 3% of cumulative abnormal return on average. Consequently, this result showed that the financial statements in Korea contain the value-relevant information that is not reflected in stock prices.