Sec. 15. (a) Except as otherwise provided, a trustee or employee of the board may not have any direct interest in the income of an investment made by the board or may not receive any pay or emolument for services connected with any investment made by the board.
(b) The board may purchase a security or financial interest issued or owned by a:
(1) custodian bank or trust company; or
(2) subsidiary, parent corporation, or holding company of a custodian bank or trust company.
(c) A trustee or employee may not become an obligor for money loaned by or borrowed from the fund.