ESMA has brought two practical market-data questions into its updated transparency manual: how to identify over-the-counter (OTC) derivatives consistently across public reports and the consolidated market-data feed, and when tick-size settings can be adjusted. The 15 October publication concerns data and trading infrastructure used by investment firms and venues; its consequences depend on the instrument and the firm’s role.[1]
The OTC identifying-reference-data guidance remains draft until RTS 2 and the consolidated-tape input/output standards enter into force. Firms can use it to prepare their data mappings; those instruments supply the legal trigger for implementation.[1]
Why a swap identifier needs accompanying data
The underlying derivatives review explains the identification problem. Contract dates embedded in the existing interest-rate-derivative ISIN can generate a different identifier as those dates change. Moving away from that treatment does not remove the dates’ economic significance: ESMA’s December 2025 final report proposed publishing effective and expiry dates as separate post-trade fields.[3]
The relevant OTC population is defined by Article 8a(2) of MiFIR. ESMA’s report distinguishes that population from exchange-traded derivatives and notes that OTC trades can occur bilaterally or on multilateral and organised trading facilities. An OTC label on a broker’s product catalogue is therefore insufficient to establish that this particular identification guidance applies.[3]
What the proposed data structure separates
| Element | Treatment | Operational significance |
|---|---|---|
| Product identification | Unique Product Identifier (UPI), under ISO 4914 for OTC derivatives within Article 8a(2); ISIN for other instruments | Identifies the product; accompanying attributes remain necessary.Source 2 |
| Interest-rate contract attributes | Reference rate, contractual term, start offset and business-term flags | Distinguishes contracts that a broad product label would combine.Source 2 |
| Effective and expiry dates | Separate post-trade fields for OTC interest-rate derivatives | Preserves the actual start and end dates of the transaction.Source 3 |
Our operational reading is that changing a code field alone cannot deliver comparable trade data. The firm’s contract record and the publication record must preserve the same economics. A stable product identifier helps group related activity; transaction dates retain the distinction between the actual contracts traded.[3]
Tick-size changes depend on the reason and timing
During estimates, the relevant authority can ask ESMA to adjust ticks for shares and depositary receipts until the first-four-weeks calculations apply, six calendar weeks after first admission or trade. Corporate actions can support recalculation where a material change in trade count is expected. For shares whose most relevant market in terms of liquidity is in a third country, regulated markets can match its tick size where the share has a non-EEA ISIN, or an EEA ISIN and trades there in local or non-EEA currency.[2]
The manual additionally distinguishes a wrong admission date from a calculated annual outcome: an erroneous date can be corrected before changing the most relevant market during estimates or first-four-weeks calculations; annual market selection cannot simply be overridden.[2]
A separate fallback is already established in ESMA’s published Q&A. When the average daily number of transactions, or ADNT, is unavailable, venues use the highest liquidity band, corresponding to at least 9,000 transactions a day. The published ADNT then applies from the following day. The fallback is a harmonisation rule, not a finding that the instrument actually trades that frequently.[5]
A data consumer needs to retain whether a liquidity band came from measured activity or the prescribed temporary default. In operational terms, the missing-data state should travel with the band: substituting a low-activity assumption would select the wrong price increment where the Q&A requires the highest band. This is an inference from the existing Q&A, not an additional rule in the 15 October update.[5]
The implementation clock remains a separate question
ESMA’s December 2025 announcement envisaged application on 1 March 2027, following Commission consideration, with a common date across the related standards ahead of the OTC derivatives tape. That remains the proposal’s timetable; the October manual supplies guidance rather than setting the commencement date.[4]
The update gives firms two distinct preparation tasks: map the OTC information required for transparency and apply the correct grounds for tick-size intervention. The next legal milestone for the derivatives guidance is entry into force of the related standards.[1]
Sources & further reading
- ESMA updates its manual on transparency with new guidance for OTC derivatives and tick-size regime European Securities and Markets Authority · 15 Oct 2026 · Accessed 15 Oct 2026
- Manual on pre-trade and post-trade transparency under MiFID II/MiFIR: 15 October 2026 edition European Securities and Markets Authority · 15 Oct 2026 · Accessed 15 Oct 2026
- MiFIR Review Final Report on transparency for derivatives, package orders and derivatives tape data European Securities and Markets Authority · 15 Dec 2025 · Accessed 15 Oct 2026
- ESMA finalises technical standards on derivatives transparency and the OTC derivatives tape European Securities and Markets Authority · 15 Dec 2025 · Accessed 15 Oct 2026
- ESMA Q&A 1630: ADNT and the default liquidity band European Securities and Markets Authority · 28 Mar 2018 · Accessed 15 Oct 2026