Mo. Rev. Stat. § 173.435: Institutions and fiduciaries may invest in bonds.

All banks, bankers, trust companies, savings banks and institutions, building and loan associations, savings and loan associations, investment companies, credit unions, insurance companies and associations, and all executors, administrators, guardians, trustees, and other fiduciaries legally may invest any sinking funds, moneys or other funds belonging to them or within their control in any bonds issued pursuant to sections 173.350 to 173.450*.