Mo. Rev. Stat. § 86.300

The board of trustees shall be the trustees of the assets of the retirement system created by sections 86.200 to 86.366 and shall have full power to hold, purchase, sell, assign, transfer or dispose of any of the securities and investments in which any of the assets shall have been invested, as well as the proceeds of such investments and any moneys belonging to the retirement system, subject to the terms, conditions and limitations provided in sections 105.687 to 105.689.