A Study on the Relationship between Insider Trading and Stock Repurchase Firms

Abstract

This study analyzes insider trading and stock price reactions before and after announcements of stock repurchases and empirically analyzes whether additional information could be provided to the market. In addition, the market response to stock repurchase announcements was analyzed to verify whether there was a difference in the entire stock market, KOSPI market, and KOSDAQ market. By examining insider trades in the stock market from 2005 to 2014, we verified that insider trading is affected by the degree to which company’s stock is undervalued. In addition, the market response to the disclosure of stock repurchase was positive, confirming that companies perceived stock repurchase as a good signal. In particular, the market reaction to stock repurchase in the KOSDAQ market is statistically significant, while that in the Kospi market is not. Finally, in all stock markets, if insider trading behavior before the announcements of stock repurchase for undervalued purposes is a strong selling position, there is no significant long-term return, indicating that market information is an incorrect signal. These findings provide evidence that insider trading behavior around stock repurchases can be used as an additional signal. © 2022, Korean Securities Association. All rights reserved.