The State Treasurer shall invest surplus money of the Fund in any security in which a savings bank may invest under State law. If the State Treasurer invests in a certificate of deposit, it shall: be interest bearing; be issued by: a bank located and authorized to do business in the State; a national banking association located in the State; or a trust company located and authorized to do business in the State; and be secured in full by a pledge of a direct obligation of the State or United States. If sale of a security in which money of the Fund is invested is in the best interest of the Fund, the State Treasurer may sell the security.