The amount of the dividend is declared special or significant in relation to the stock price. For this reason, the ex-dividend date is set one stock trading day after the payment date. The stock will trade on an ex-distribution basis, adjusted for the amount of the dividend paid one trading day after the payment date. The determining factor for a special or significant dividend is usually when the dividend is 20% or greater in relation to the underlying price of the stock/security.
To be entitled to a special dividend, you need to be a stockholder on the record date. To be a stockholder on the record date, your purchase would have needed to be made a minimum of three stock trading days prior to the date of record or record date.
In the case of special or significant dividends, the stock trades without the dividend from the record date, through the Payment Date, then adjust for the dividend paid and starts trading on an ex-distribution basis one stock trading day after the Payment Date. To be entitled to receive the dividend, it is required that you be a stockholder on the record date and hold your stock thru the payment date in order to receive the dividend. When a special or significant dividend is being paid selling your stock between the record date and payment date relinquishes your right to the dividend.
The earliest you can sell your stock and still be entitled to the special dividend is one day after the payment date, or the date the stock begins trading on an ex-distribution basis.