Whenever there is in the State Treasury any funds belonging to the workers' compensation fund not likely, in the opinion of the commission, to be required for immediate use, it is the duty of the Investment Management Board to invest the funds as prescribed in section two of this article. Whenever it becomes necessary or expedient to use any of the invested funds, the Investment Management Board, at the direction of the commission, shall collect, sell or otherwise realize upon any investment to the amount considered necessary or expedient to use.