Mo. Rev. Stat. § 388.200

No person holding stock in any such company, as personal representative, conservator, or trustee, and no person holding such stock as collateral security shall be personally subject to any liability as a stockholder of such company; but the person pledging such stock shall be considered as holding the same, and shall be liable as a stockholder accordingly; and the estates and funds in the hands of such personal representative, conservator, or trustee shall be liable in like manner, and to the same extent, as the testator or intestate of the protectee or person interested in such fund would have been, if he had been living and competent to act, and held the same stock in his own name.