8.IV.1.4 Interim conclusion

The introduction of the MiFID I concept of a ‘large in scale transaction’ (relevant for deferral of post-trade data publication) resulted in a more data-driven transparency regime compared to the ISD. The EU realized that the data-driven approach of MiFID I would require a greater operational quality. NCAs needed to (1) perform equity post-trade transparency calculations and estimates and (2) have data available to perform the calculations and estimates in practice. The MiFID I text covered harmonised provisions on how the calculations and estimates needed to take place. The MiFID I text was mainly the result of CESR providing drafts. CESR also provided guidance in the form of an internal guidebook (e.g. how to collect the data, calculation methodologies, and so forth). The EU aim, both apparent in the MiFID I text and CESR guidebook, was to ensure NCAs would perform the calculations and estimates in a similar way, as well as being able to perform the calculations and estimates in practice.1 The underlying goal was a common degree of equity post-trade transparency (similar calculations/estimates across the EU), a related level playing field, and a regime that would work in practice (data collection and calculation).