The Relationship between Accruals Anomaly and Insider Trading in Korea Stock Market
Authors:   Asia-Europe Perspective Association, Yoon Sung-Yong , Oh Won-Jung 
Published: June 2018

This research analyzes the relationship between accruals anomaly and insider trading. The profits earned through insider trading are directly influenced by the price at which insiders buy and sell the securities of the company concerned. There exist several ways for insiders to have an impact on the price of security concerned and, as a primary means, insiders may consider an intentional earnings management. For those insiders who have a plan of selling their securities in the future, there is a lure to affect the price of security positively by managing their profits upwardly, which enables them to get an opportunity of earnings by selling the securities at a higher price. For those insiders who have an intention of buying the securities of the company concerned, there is also a lure to affect the price of security negatively by managing their gains downwardly.
As a result, insiders are able to trade the stocks at a better condition by purchasing the stocks at a lower price. That is, this research is focused on analyzing whether there is a constant accruals anomaly by insider trading through earning adjustment, which is carried out when insiders sell their holdings at a higher price or buy stocks at a lower price. The actual analysis on December’s KSE listed firm of non-financial business from 2002 to 2008 indicates that the firms with higher accruals highly converged at sales transaction at the relation between the pattern of insider trading and accruals, and there is a significant negative correlation between discretionary accruals and NPR, and there is a significant negative correlation with purchase transaction even when separating sales and purchase transaction and included to the model, and also there is significant positive correlation with sales transaction, which underpins The hypothesis of this research that the discretionary accruals has the negative (positive) correlation with insider’s purchase transaction (sales transaction). On the other hand, the important consideration explaining the anomaly is the effect based on the growth of corporation’s basic fundamentals. Hence, on this research, I did regression analysis controlling other determinant (such as cash flow followed by sales, the rate of change in the number of employee, firm size, ratio of leverage, litigation prone industries) set aside from discretionary accruals to analyze whether there is a constant relation between discretionary accruals and insider’s sales(purchases) transaction. As a result, I found out purchase (sales) transaction is related to very low (high) accruals, which supports the hypothesis of this research once again. In other words, insiders manage the earnings upward before sales transaction to maximize it and manage the earnings downward before purchase transaction.
This research is of significance in that it shows practically that insider trading functions as a mean of earning adjustment so that accrual anomaly could happen under the stock market at home and abroad. In addition, unlike precedent research, this research differentiates itself from others in that the level of other determinants other than accruals has an impact on the relation between earning adjustment and insider trading. Not only does this research provide a role of presenting a theoretical basis of study on accruals anomaly, but also it is expected to have an practical implication for investors, financial audits, and auditors.
First of all, to investors, the reported earnings of the firm with insider trading likely has a higher chance to do earning adjustment than that of one without insider trading and can be used as an useful information to estimate the quality of earnings of the firm involved so that it has the significance to set a investing strategy of obtaining excess earning rate exceeding average earning rate by using this anomaly phenomena.