Tex. Educ. Code § 52.19

All money in the Texas college interest and sinking fund and in each board interest and sinking fund, including any reserve portion, and all money in the Texas Opportunity Plan Fund and in the student loan auxiliary fund in excess of the amount necessary for student loans, and all money in each board student loan fund shall be invested by the comptroller in the investments prescribed by board resolution. The board shall furnish to the comptroller a copy of the resolution prescribing authorized investments. The board may sell any instruments owned in the Texas college interest and sinking fund, a board interest and sinking fund, the Texas Opportunity Plan Fund, the student loan auxiliary fund, or a board student loan fund at the prevailing market price. Income from these investments may be deposited in any of those funds.