HOLDING OFFICES (SIC 671) Establishments primarily engaged in holding or owning the securities of banks for the sole purpose of exercising some degree of control over the activities of bank companies whose securities they hold. Companies holding securities of banks, but which are predominantly operating the banks, are classified according to the kind of bank operated. Establishments primarily engaged in holding or owning securities of companies other than banks, for the sole purpose of exercising some degree of control over the activities of the companies whose securities they hold. Companies holding securities, but which are predominantly operating companies, are classified according to the kind of business operated.