Mo. Rev. Stat. § 400.8-508: Duty of securities intermediary to change entitlement holder's position to other form of security holding.

A securities intermediary shall act at the direction of an entitlement holder to change a security entitlement into another available form of holding for which the entitlement holder is eligible, or to cause the financial asset to be transferred to a securities account of the entitlement holder with another securities intermediary. A securities intermediary satisfies the duty if:

(1) The securities intermediary acts as agreed upon by the entitlement holder and the securities intermediary; or

(2) In the absence of agreement, the securities intermediary exercises due care in accordance with reasonable commercial standards to follow the direction of the entitlement holder.