In the discussions leading up to the markets in financial instruments directive, financial conglomerates and exchanges fiercely debated the extent to which European securities regulations should allow for in-house matching of customers’ orders. The scope of this debate was extended to include the issue of whether securities exchanges should own and control the clearing houses and settlement organisations.

Large financial companies received so many customer orders, they felt they should have the right to match such orders internally and not be forced to go through the exchange systems. These banks claimed that, by matching in-house, they could avoid incurring expensive fees for a service they did not require. The control exchanges exercised over clearing houses was considered an abuse of power.