The board of trustees, in the exercise of its discretion to manage the assets of the retirement system, may select one or more commercial banks, depository trust companies, or other entities to serve as custodian or custodians of the system's cash or securities pending completion of an investment transaction and may authorize the custodian to invest the cash so held in such short-term securities as the board of trustees determines.
Tex. Gov't. Code § 845.302