(a) Bonds issued under this subchapter are legal and authorized investments for:
(1) a bank;
(2) a savings bank;
(3) a trust company;
(4) a savings and loan association;
(5) an insurance company;
(6) a fiduciary;
(7) a trustee;
(8) a guardian; and
(9) an interest and sinking fund or other public fund of the state or of an agency, subdivision, or instrumentality of the state, including a municipality, county, school district, special district, public agency, and body politic.
(b) The bonds are eligible and lawful security for the deposits of public funds of the state or of an agency, subdivision, or instrumentality of the state, including a municipality, county, school district, special district, public agency, and body politic. The bonds may secure those deposits in an amount up to the value of the bonds, if accompanied by all appurtenant unmatured interest coupons.