An institutional buyout (IBO) occurs when a controlling interest in a company is acquired from the shareholders by an institutional investor, such as private equity or venture capital firms or commercial banks. The sale of privately held corporations is also a viable alternative to buyouts of publicly traded firms, such as in a "going private" trade. The polar opposite of an institutional buyout (IBO) is the management buyout (MBO) in which the existing management trades all or part of the company.