실적발표가 IT기업과 비IT기업의 주가에 미치는 영향에 대한 연구: 전망이론을 바탕으로

There have been many studies to evaluate the profitability of IT investments. Among that studies, event study methodology, which empirically verifies the change of stock price after related events, has been used by some researchers. Prior studies in this area tried to identify the relationship between IT investment announcements and the change of IT companies' stock prices. In this study, we tried to prove the different response between IT companies' stock prices and non-IT companies' stock prices after earning announcement based on prospect theory. Our test testified that in the year 2007, economic stabilization period, the stock prices of IT companies were changed by earning announcements; however, the stock prices of traditional companies did not change. Because relatively small and young IT companies are more unstable and have more uncertainty than traditional companies, the responsiveness of stock prices of IT companies are more sensitive than traditional companies. On the other hand, in the year 2008, economic stagnation period, both the stock prices of IT companies and non-IT companies were changed. This result reveals that without distinction of IT or non-IT, the responsiveness of stock market on new information is significant in the depression period.