Sec. 21. "Stock benefit plan" means any defined benefit plan or defined contribution plan. The term includes:
(1) an employee stock ownership plan;
(2) a stock bonus plan;
(3) a profit-sharing plan; or
(4) any other plan of a mutual holding company or any of its subsidiaries or affiliates;
whether or not the plan, with its related trust, meets the qualifying requirements under section 401 of the Internal Revenue Code.