Every person who is directly or indirectly the beneficial owner of more than ten per cent of any class of any equity security of a domestic stock insurance company or who is an officer, as defined by the Insurance Commissioner, or a director of such company shall file in the office of the commissioner on or before December 31, 1965, or within ten days after he becomes such beneficial owner, director or officer, whichever is later, a statement, in such form as the commissioner may prescribe, of the amount of all equity securities of such company of which he is the beneficial owner, and within ten days after the close of each calendar month thereafter, if there has been a change in such ownership during such month, 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 such calendar month.