(19)Pursuant to Directive 2014/65/EU, a systematic internaliser should not be allowed to bring together third party buying and selling interests in functionally the same way as a trading venue. A systematic internaliser should not consist of an internal matching system which executes client orders on a multilateral basis, an activity which requires authorisation as a multilateral trading facility (MTF). An internal matching system in this context is a system for matching client orders which results in the investment firm undertaking matched principal transactions on a regular and not occasional basis.