Every person who is directly or indirectly the beneficial owner of more than 10 percent of any class of any equity security of a domestic stock insurer or who is a director or an officer of such insurer shall file in the office of the Commissioner within ten days after the person becomes the beneficial owner, director, or officer a statement in such form as the Commissioner may prescribe of the amount of all equity securities of the insurer of which the person is the beneficial owner; and within ten days after the close of each calendar month after the person becomes the beneficial owner, director, or officer, if there has been a change in such ownership during such month, the person shall file in the office of the Commissioner a statement in such form as the Commissioner may prescribe indicating his ownership at the close of the calendar month and such changes in his ownership as have occurred during that calendar month.