 As is the case with all dividends, if you sell your stock prior to the ex-dividend date, within the due bill period, you relinquish your right to the dividend.The earliest you can sell your stock and still be entitled to the special dividend is the date the stock begins trading on an ex-distribution basis, or generally one day after the dividend payment date, on the ex-dividend date.In simplest terms, ownership on the "record date" usually, but not always (because of the case of large special dividends), determines who is entitled to a dividend.