S.C. Code § 34-21-320
The trust institution shall invest the moneys of an estate in such common trust fund by adding them thereto, and by apportioning a participation therein to such estate in the proportion that the moneys of the estate added thereto bears to the aggregate value of all the securities of such fund at the time of such investment, including in such securities the moneys of the estate so added. The withdrawal of a participation of such common trust fund shall be on the basis of its proportionate interest in the aggregate value of all the securities of such fund at the time of such withdrawal, as hereinafter provided. The participating interest of any estate in such common trust fund may, from time to time, be withdrawn in whole or in part by the trust institution, and shall be so withdrawn within a period of three months following the written request so to do of any person acting with the trust institution in a fiduciary capacity.
Upon such withdrawals, the trust institution may make distribution in cash or ratably in kind, or partly in cash or partly in kind; provided, that all such distribution as of any one time shall be made on the same basis.
S.C. Code § 34-21-320