S.D. Codified Laws § 51A-6A-21
The shares of stock and ownership units of any trust company are personal property and shall be transferred on the books of the trust company in such manner as the bylaws or operating regulations of the trust company may direct. No stock or ownership units may be transferred on the books of the trust company when the trust company is in a failing condition, or when its capital is impaired, except upon approval of the director. If a transfer of shares of stock of any trust company, or holding company that owns a majority of the outstanding shares of a trust company, occurs which results through direct or indirect ownership by a stockholder or an affiliated group of stockholders of ten percent or more of the outstanding stock of the trust company, or holding company that owns a majority of the outstanding shares of a trust company, and if additional shares of stock of the trust company are transferred to such stockholders, affiliated group of stockholders, or holding company, the president or other chief executive officer of the trust company shall report the transfer to the director within ten days after transfer of the shares of stock on the books of the trust company.
SDCL 51A-6A-21