The bank holding company organization increasingly is being managed so as to take advantage of the synergies between its component parts in order to deliver better products to the market and higher returns to stockholders. Such synergies cannot occur if the model of the holding company is one in which the parent is just, in effect, a portfolio investor in its subsidiary.
Indeed, virtually all of the large holding companies now operate as integrated units and are managed as such, especially in their management of risk. One could argue that regulators should be interested only in the entities they regulate and, hence, review the risk evaluation process only as it relates to their regulated entity.