Mo. Rev. Stat. § 375.422
Every person who is directly or indirectly the beneficial owner of more than ten percent of any class of any equity security of any insurance company organized under the laws of this state and having capital stock, or who is a director or an officer of such company, shall file in the office of the director of the department of commerce and insurance of the state of Missouri on or before January 1, 1966, or within ten days after he becomes such beneficial owner, director or officer, a statement in such form as the director 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, any such person shall file in the office of the director a statement, in such form as the director may prescribe, indicating his ownership at the close of each such calendar month and such changes in his ownership as have occurred during such calendar month.
§ 375.422, RSMo