40 ILCS 5/14-137
The Treasurer of the State of Illinois shall be, ex-officio, the treasurer of the system. He shall: (a) act as official custodian of the cash and securities belonging to the system and provide adequate safe deposit facilities for their preservation and hold such cash and securities subject to the order of the board; (b) receive all items of cash belonging to the system, as the same are transmitted by the Executive Secretary of the system, including member contributions, State contributions, interest and principal payments on investments and other income accruing to the system, and deposit all such amounts in a special trust fund for the account of this system, and submit a monthly report to the board of all such transactions; (c) make payments for purposes specified in this Article upon warrants or direct deposit transmittals of the State Comptroller issued in accordance with vouchers signed by the Executive Secretary pursuant to authorization of the board.
The treasurer shall furnish a corporate surety bond, acceptable to the board in the penal sum of $50,000, conditioned for the faithful discharge of his duties, and to deliver up all moneys, securities, papers, books, records and other property appertaining to his office as treasurer of the system, whole, safe and undefaced, to his successor in office. Whenever the board deems the amount of the bond insufficient, it may require an increase to a penal sum not to exceed $100,000. All reasonable charges incidental to the procuring and giving of such bond shall be paid by the board.
Any cash accruing to the special trust fund of the system not required for current operating expenditures shall upon direction by the Executive Secretary be transferred immediately to the said Illinois State Board of Investment for purposes of permanent investment for the system. Until such transfer is made, those funds shall be invested temporarily by the Treasurer on behalf of the system and interest earned thereon shall be credited to the trust fund of the system.
40 ILCS 5/14-137