MiFIR post-trade transparency: three checks for a Luxembourg bank

Regulation (EU) No 600/2014 of 15 May 2014 on markets in financial instruments (hereafter, MiFIR) governs MiFIR post-trade transparency: the obligation to disclose specified details of an executed transaction to the market after execution. For transactions within Article 21(1) MiFIR, those details include the price, volume and time of the transaction.

Where a Luxembourg bank executes an in-scope derivative outside a trading venue—that is, outside a regulated market, multilateral trading facility or organised trading facility—it must answer three separate questions: may publication be deferred, which party must publish, and which Commission de Surveillance du Secteur Financier (CSSF) formality applies?

Determine the applicable deferral

A deferral postpones publication; it does not remove the publication obligation.

As at 15 July 2026, derivative deferrals remain subject to transitional arrangements. Article 54(3) MiFIR and Article 1a of Commission Delegated Regulation (EU) 2017/583 of 14 July 2016 on transparency requirements concerning, among other instruments, derivatives (hereafter, RTS 2) preserve Articles 8 and 11 RTS 2 and the pre-28 March 2024 MiFIR provisions which those articles supplement for derivatives. Firms must therefore apply the retained derivative rules during the transition, rather than relying only on the revised MiFIR regime.

The CSSF’s MiFID II/MiFIR Questions and Answers, version of 13 July 2026 (hereafter, CSSF Q&A), Question 4.1.1, permits deferral notably where:

• the transaction is large in scale compared with the normal market size;
• the instrument or class of instruments does not have a liquid market; or
• the transaction exceeds the applicable size-specific-to-the-instrument threshold and immediate disclosure could expose liquidity providers to undue risk.

The bank must identify the relevant instrument class, applicable threshold, permitted deferral period and publication arrangements for each transaction.

Allocate publication responsibility

A designated publishing entity is an investment firm granted that status by its competent authority for specified classes of financial instruments. An approved publication arrangement (APA) is the authorised service through which the transaction details are made public.

Under Article 21a(2) and (3) MiFIR:

• if only one party is a designated publishing entity, that party must publish through an APA;
• if both parties, or neither party, have that status, the seller must publish.

The bank must therefore check the status of both parties for the relevant instrument class.

Systematic internaliser status must be assessed separately. A systematic internaliser is, broadly, an investment firm dealing on own account when executing client orders outside a trading venue on the organised and systematic basis described in Article 4(1)(20) of Directive 2014/65/EU (MIFID II). That status carries separate requirements, but it does not replace the publication-allocation test in Article 21a MiFIR.

Complete the correct CSSF formality

The two CSSF email addresses serve different purposes:

• a bank intending to use the outside-venue derivative deferral must notify mmifid2@cssf.lu;
• an entity that qualifies or opts in as a systematic internaliser must send the dedicated form to mifid2@cssf.lu;
• an entity requesting designated-publishing-entity status must send the dedicated form to mifid2@cssf.lu.

Under CSSF Q&A Questions 4.2.1 and 4.2.2, designated-publishing-entity status is not automatic: the CSSF grants it upon request for specified classes of financial instruments.

The practical sequence is clear: determine whether the transaction qualifies for deferred publication, identify the party responsible for publication, and complete the corresponding CSSF formality.

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References:

• Commission de Surveillance du Secteur Financier, MiFID II/MiFIR Questions and Answers, version of 13 July 2026, Questions 4.1.1, 4.2.1 and 4.2.2, pages 14–17 (https://www.cssf.lu/wp-content/uploads/QA-MiFIDII_MiFIR.pdf)
• Regulation (EU) No 600/2014 of 15 May 2014 on markets in financial instruments, Articles 21, 21a and 54(3) (https://eur-lex.europa.eu/eli/reg/2014/600/2024-03-28/eng)
• Commission Delegated Regulation (EU) 2017/583 of 14 July 2016, Articles 1a, 8 and 11, consolidated version applicable from 2 March 2026 (https://eur-lex.europa.eu/eli/reg_del/2017/583/2026-03-02/eng)
• Directive 2014/65/EU of 15 May 2014 on markets in financial instruments, Article 4(1)(20) (https://eur-lex.europa.eu/eli/dir/2014/65/2025-01-17/eng)