Mo. Rev. Stat. § 375.370: Collateral to be assigned to company.

All stocks and other evidence of indebtedness, except such as are transferable by delivery, held by insurance companies doing business in this state, as collateral for moneys loaned or other obligations, shall be regularly assigned and transferred over to said companies by the corporations or individuals issuing the same, and shall be surrendered by such companies only when the obligations of the assignors shall have been permanently and satisfactorily fulfilled and discharged.