If the Depositor is the Beneficial owner of the Funds and the Custodian is the Trustee, how is this relationship defined?

As outlined in MAM’s agreement with the partner banks, the notional account established by MAM as Distributor (Custodian) with the bank represents the Client’s beneficial interest in the Deposit. No person other than an Investor has or shall have a direct or indirect beneficial interest in each such Deposit.  MAM shall not, in the performance of its obligations under said agreement, exercise any discretion or take any action or omit to take any action that might undermine its bare trustee status or might otherwise act as a fetter on the Investors' rights as beneficial owners to capital and income arising under the Deposit.