• 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.

• International Area Studies Review
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• v.15 no.1
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• pp.87-106
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• 2011

Using an event study, this paper investigates stock price reactions on Korean listed firms' convertible bond (CB) issue announcements over the sample period of January 2000 to November 2007. This study finds that on the Korean Security market, the CB issue announcements are associated with an increase in shareholder wealth on the announcement date. An information leakage by insider traders is also observable at preannouncement dates. Unlike the prior studies that indicate a prevailing negative effect on the announcements, this paper shows that domestic CB issue announcements as well as offshore ones yield a positive impact on the stock prices. This presents that in terms of stock price reactions to the CB issue announcements, the two CB issue markets show the positively same effects on shareholder wealth for the post-2000 period. For its drivers, this paper suggests that on the Korean market, firm size have negative relationship with the increase in the wealth incurred by the announcements. By contrast, an issue to maturity, a growth opportunity, and a relative issue size make a positive impact on it.