Ngoc and Cuong (2016) identified that Ex Dividend date has a significant impact on the stock returns around the announcement
date. The stock price follows an uptrend as long as the ex-dividend date approaches and then starts decreasing from this date
onwards. The purpose of this study was to determine the impact of dividend policy on the stock return by investigating reaction of
the stock price on the dividend announcement date and the ex-dividend date. This secondary research has 1962 observations from
432 companies listed on the Vietnam stock exchange as its sample size: ranging from a period of 2008 to 2015. Cumulative average
abnormal return and T-test are the statistical tool used for the conceptual research. The conclusion of the study was: the effects of
dividend announcement on the stock return of the companies are positive around the announcement date.
Campbell and Beranak (1955) revealed that the fall in the stock prices on the Ex dividend date is approximately about 90% of the
dividend declared.