Following trading hours on April 25, 2017, Costco Wholesale Corporation (symbol: COST) announced that it would pay a special dividend of $7.00 per share in early May. The ex-dividend date for this special dividend was May 8, 2017. Thus, if you held COST stock at the beginning of May 8, 2017, you would have been paid the special dividend of $7 per share. Otherwise, you would have not received the special dividend. The purpose of this question is to examine the COST price reaction on the announcement date and ex-dividend date.

a) Download daily price data for COST from Yahoo! Finance for the period April 3, 2017 to June 1, 2017. Graph the price series (use the closing price, not the adjusted closing price) and highlight the day the special dividend was announced and the ex-dividend day.