A corporate credit union is a credit union whose members consist primarily of other credit unions and whose purposes are to:
(1) accumulate and prudently manage the liquidity of its member credit unions through interlending and investment services;
(2) act as an intermediary for credit union funds between members and other corporate credit unions;
(3) obtain liquid funds from other credit union organizations, financial intermediaries, and other sources;
(4) foster and promote in cooperation with other state, regional, and national corporate credit unions and credit union organizations or associations the economic security, growth, and development of member credit unions; and
(5) perform such other financial services of benefit to its members that are authorized by the Commissioner.