8.III.1.4 Responsibility for publication

The MiFID I Implementing Regulation set out the responsibility for investment firms in making the post-trade information public. Such a provision was not deemed necessary for RMs and MTFs (see paragraph 2.1 above). Investment firms trading outside an RM or MTF were permitted to make an agreement who would publish the post-trade data. The possibilities varied from: (a) the selling investment firm; (b) the firm that acted on behalf of or arranged the transaction for the seller; (c) the firm that acted on behalf of the buyer; or (d) the firm that bought the share.1 In case an agreement was absent, the responsibility for publication was determined by the sequence from point (a) to point (d).2 The parties needed to take all reasonable steps to ensure that the transaction was made public as a single transaction.3 MiFID I specified that for those purposes two matching trades entered at the same time and price with a single party interposed needed to be considered to be a single transaction.4 CESR provided formally non-binding guidance to ensure there would be no duplication of post-trade data publication.5