11.III Consolidation of equity pre- and post-trade data

The ISD relied on market forces to provide consolidation services for the collection and publication of trading activity in one place. National law could provide the parameters for consolidation, which in practice resulted in a market-driven approach (bottom-up). CESR stated that, despite the lack of harmonized provisions in this area, in most Member States, market participants had access to a consolidated view of trading in shares.1 CESR said this was mainly the result of the common situation where only one RM traded a particular share. In Member States where there was more than one trading platform for a particular share, the RMs and/or data vendors (e.g. Reuters or Bloomberg) often consolidated the equity pre- and post-trade data.2

CESR also identified shortcomings. A consolidated view of EEA cross-border trading in particular shares traded on multiple venues was typically limited to the larger (so-called blue-chip) multi-listed shares only, thereby excluding smaller companies.3 In addition, RMs and data vendors used a variety of publication standards. This meant that the consolidation of pre- and post-trade from many different sources required the conversion of different publication standards into one standard (costly to ‘map’).4