(13)The rationale of the ancillary activity tests is to check whether persons within a group that are not authorised in accordance with Directive 2014/65/EU should apply for an authorisation due to the relative or absolute size of their activity in commodity derivatives, emission allowances and derivatives thereof. The ancillary activity tests thus determine the size of activities in commodity derivatives, emission allowances and derivatives thereof which persons within a group may carry out without authorisation under Directive 2014/65/EU due to those activities being ancillary to the group's main business. It is therefore appropriate to calculate the size of the ancillary activity of the group by using criteria which exclude the activity carried out by group members which are authorised in accordance with that Directive in order to assess the size of genuine ancillary activity carried out by unauthorised group members.