4.For the purposes of paragraph 1, institutions may establish themselves buckets for a given curve, surface or a cube where all of the following conditions are met:
(a)the buckets cover the whole curve, surface or cube;
(b)the buckets are non-overlapping;
(c)each bucket contains exactly one risk factor that is part of the calculation of the theoretical changes in the portfolio’s value of one of the trading desks of the institution to assess compliance with the profit and loss attribution requirements laid down in Article 325bg of Regulation (EU) No 575/2013.