Notwithstanding any other provision of law, the board may retain a bank or trust company to serve as custodian for safekeeping, delivery, securities valuation, investment performance reporting, and other services in connection with investment of the retirement fund. Notwithstanding Section 13340, all moneys in the fund are continuously appropriated, without regard to fiscal years, for payments which shall be made upon warrants drawn by the Controller upon demands made by the board. Upon demand of the board, warrants shall be drawn for the purpose of making payments by electronic fund transfers.