(128)It is appropriate to set the criteria for determining when the operations of a regulated market, an MTF or an OTF are of substantial importance in a host Member State so as to avoid creating an obligation on a trading venue to deal with or be made subject to the supervision of more than one competent authority where this would not be necessary according to Directive 2014/65/EU. For MTFs and OTFs, it is appropriate that only MTFs and OTFs with a significant market share be considered as being of substantial importance, so that not any relocation or acquisition of an economically insignificant MTF or OTF automatically triggers the establishment of the cooperation arrangements set out in Article 79(2) of Directive 2014/65/EU.