9.IV.2.2.5 Storage of the data

MiFIR requires the reporting parties (i.e. RMs, MTFs, and APAs and CTPs) to store ‘the necessary data’ for a sufficient period of time.1 The requirement is specified in a MiFIR Delegated Regulation. RMs, MTFs, APAs, and CTPs need to store all data required to calculate, monitor or adjust the MiFID II equity post-trade transparency thresholds and parameters (average daily turnover), regardless whether or not the data has been made public (e.g. published through a MiFID II Database, see paragraph 3 below).2MiFID II requires RMs, MTFs, APAs, and CTPs to store the data for at least three years.3 The rationale behind the storage requirement is to allow NCAs (or ESMA in case of delegation) to perform accurate calculations.4 The storage of data enables the NCA (or ESMA in case of delegation) to perform consistency checks (for a period of at least three years), for example, for the purposes of identifying and removing erroneous data.5