24 Pa. Stat. § 26-2603
The State Board of Education shall promptly invest, and keep invested as constantly as possible, to the best advantage of the State School Fund, all appropriations, devices, gifts, and other receipts for this purpose, as a permanent State School Fund. Investments of the permanent State School Fund may be made only in bonds properly issued by the Government of the United States, the Commonwealth of Pennsylvania, a school district in this Commonwealth, or in municipal bonds in which savings banks of Pennsylvania are authorized by law to invest their deposits, and all such investments must be first approved by the Auditor General.
Such investments shall be converted into cash whenever necessary to make the payments provided for in this article, and to pay for salaries and wages, purchase of supplies and other necessary and pertinent expenses of administration of this article.
24 P.S. § 26-2603