Sec. 4.07. INVESTMENT OF SURPLUS. (a) Subject to Section 4.071 of this article, if the board determines that there is in the fund a surplus exceeding a reasonably safe amount to take care of current demands on the pension system, the board may invest or direct the investment of the surplus for the sole benefit of the pension system.

(b) In making investments and supervising investments, trustees shall exercise the judgment and care under the circumstances then prevailing that persons of ordinary prudence, discretion, and intelligence exercise in the management of their own affairs, not in regard to speculation but in regard to probable income from the assets as well as the probable safety of their capital.

(c) The board has the ultimate responsibility for the investment of funds. The board may exercise this responsibility directly by purchasing or selling securities or other investments, or it may exercise discretion in determining the procedure that it deems most efficient and beneficial for the pension system in carrying out the responsibility. The board may contract for professional advisory services regarding the purchase or sale of securities or other investments pursuant to Section 3.02 of this article. A professional advisory service shall receive such compensation as may be determined by the board in accordance with Section 4.01 of this article.

(d) The board also has the authority to contract for professional investment management services. Any contract that the board makes with an investment manager shall set forth the board's investment policies and guidelines. A professional investment management service shall receive such compensation as may be determined by the board in accordance with Section 4.01 of this article.

(e) The board, in exercising its control, may at any time, and shall at frequent intervals, monitor the investments made by any investment manager and shall enforce full compliance with the requirements of the board.

(f) If the board contracts for and receives professional advisory services or professional investment management services, the board has no greater liability under the terms of this section than otherwise provided for under the Government Code or the Texas Trust Code.

(g) A bank or trust company that has custody and trustee powers and a contract with the board to provide assistance in making investments shall be the custodian or master trustee of any of the securities or other assets of the fund. Pursuant to Section 4.06 of this article, the board may designate a bank to serve as custodian or master trustee, or subcustodian or submaster trustee, to perform the customary duty of safekeeping as well as duties incident to the execution of transactions. As the demands of the pension system require, the board shall withdraw from the custodian or master trustee money previously considered surplus in excess of current cash and proceeds from the sale of investments. The money may without distinction be used for the payment of benefits pursuant to each of the plans within the pension system and for other uses authorized by this article and approved by the board.

(h) The board through policy shall establish an investment advisory committee composed of trustees and outside investment professionals to review investment related matters as prescribed by the board and make recommendations to the board. A majority of the members of the committee established under this subsection must be outside investment professionals.