EU Short Selling Regulation Disclosure Thresholds

When to Use

Use this skill when a strategy, prime-brokerage reporting stack or risk system holds net short positions in shares admitted to trading on an EU/EEA trading venue, and you need to know what Regulation (EU) No 236/2012 requires today.

It answers two separate questions and keeps them separate:

• Arts. 5 and 6 — disclosure. A net short position reaching 0.1% of issued share capital, and each 0.1% above that, is privately notified to the relevant competent authority (RCA); at 0.5% and each 0.1% above, it is also publicly disclosed. The 0.1% notification figure is not the original text — Commission Delegated Regulation (EU) 2022/27 permanently lowered it from 0.2% with effect from 31 January 2022.
• Art. 12 — execution. A short sale of a share may only be entered into where the seller has borrowed it, has an agreement to borrow it, or holds a third-party arrangement confirming the share is located with a reasonable expectation of settlement.

Both surfaces are evidence-backed against the regulation, the Delegated and Implementing Regulations, and ESMA's Q&A. Where the rule depends on something this module cannot know — the RCA's local timezone, that Member State's trading calendar — it says so instead of guessing.

When NOT to Use

• For sovereign debt or sovereign CDS. Arts. 7 and 14 have their own regime: the notification thresholds are set per sovereign issuer by ESMA as absolute amounts, not as a percentage of issued share capital, and positions are duration-adjusted. Nothing here applies to them.
• As a delta-adjustment calculator. The Arts. 5/6 position is a delta-adjusted measure (Delegated Regulation (EU) No 918/2012 Annex II Part 1) covering cash, derivatives, ETF look-through and ADRs/GDRs. This engine consumes delta-adjusted share equivalents; it does not price options. Feeding it raw share counts while holding options understates the position and misses filings.
• As the aggregation layer. Delegated Regulation (EU) No 918/2012 Arts. 12-13 set where the calculation happens — per legal entity, per fund/sub-fund for management entities, and at group level. Run this engine on an already-correctly-aggregated position; running it on one desk's book computes a percentage nobody has to report.
• Outside the EU/EEA regime. The UK, Switzerland and other jurisdictions run separate short-selling regimes with their own thresholds, forms and deadlines. The class name says EU for a reason.
• As the filing transport. It decides what is owed and by when. Each NCA has its own portal, form and authentication; nothing here submits anything.
• Without checking scope first. Shares whose principal trading venue is in a third country are outside Arts. 5, 6 and 12 entirely (Art. 16). ESMA publishes the exempted-shares list; a US-principal-venue share cross-admitted in Germany generates no EU obligation, and reporting one anyway is a false filing.

Prerequisites

• Python 3.10+ (zoneinfo; stdlib only). On platforms with no system IANA database — Windows in particular — the tzdata package must be installed or deadline computation raises with that instruction.
• Delta-adjusted long and short share equivalents per issuer (long_shares_qty, short_shares_qty), aggregated at the correct reporting level.
• Issued share capital = total of ordinary and preference shares, all classes, irrespective of voting rights (Art. 2(1)(l); ESMA Q&A A6.6). Use the figure the issuer/NCA publishes, not a vendor's free float.
• The relevant competent authority and the IANA timezone of its Member State (nca_timezone, e.g. Europe/Helsinki), plus a next_trading_day callable implementing that Member State's trading calendar. Without both, no deadline instant is produced.
• The last percentage notified for this issuer (previously_notified_percentage), or None. Without it the engine cannot distinguish a fresh crossing from a position sitting inside a band it already reported.
• Scope flags: Art. 16 exempted-share status and Art. 17 market-making status (the latter requires 30 calendar days' prior written notice to the home competent authority before it may be relied on).

Workflow

1. Scope the instrument before calculating anything. Check the share against ESMA's exempted-shares list (Art. 16) and your Art. 17 notification status.
   • Decision point — exemption is checked first, not last. An exempt share returns OUT_OF_SSR_SCOPE with no action. Computing a percentage and filing it "to be safe" puts a position on a public register that the regulation does not place there.
2. Compute the net short position at the Art. 9(2) relevant time — midnight at the end of the trading day — as delta-adjusted short minus delta-adjusted long, over issued share capital.
   • Decision point — intraday peaks are not the reported figure. The obligation attaches to the end-of-day position; a position that touches 0.6% at 11:00 and closes at 0.3% is a 0.3% notification.
3. Truncate to two decimal places. ESMA Q&A A5.6: 0.3199% is reported as 0.31%, by truncation, and the threshold test runs on the truncated figure.
   • Decision point — never round up into a band. 0.49999% is 0.49% and owes a private notification only. Rounding it to 0.5% publishes a position on the public register that is not required to be there, and files a figure that does not match the holder's books.
4. Map the truncated figure to a band (0.10%, 0.20%, 0.30%, …) and compare with the band last notified.
   • Decision point — a move inside an already-notified band owes nothing (ESMA Q&A A5.7). 0.30% drifting to 0.3989% is not a new notification.
   • Decision point — falling below a threshold is itself notifiable. Dropping from 0.35% to 0.05% requires a notification, and dropping out of the 0.5% regime requires the public register to be updated, not just the NCA.
   • No prior notification on record is treated as "not yet notified" — a position in a band is reported as due. That is the conservative direction, and it is why the field should be populated from your filing history rather than left None.
5. Resolve the deadline in the RCA's local time. Art. 9(2) requires filing by 15:30 on the following trading day; ESMA Q&A A5.2 confirms that is the local time and trading-day calendar of the Member State of the relevant competent authority.
   • Decision point — "15:30 CET" is not the rule and is wrong for much of the Union. 15:30 in Helsinki is 12:30 UTC; 15:30 in Berlin is 13:30 UTC. A CET-based scheduler files an hour late to every EET competent authority, and DST transitions move both.
   • Without a configured timezone or trading calendar the engine returns no deadline instant and says which piece is missing. Fail closed and fix the configuration; do not substitute a default.
6. Gate short sale orders separately with evaluate_short_sale_order. Art. 12 needs a borrow, an agreement to borrow, or a located-and-confirmed arrangement, evidenced in a durable medium (ITS 827/2012 Arts. 5-7).
   • Decision point — an Art. 12 problem never cancels an Art. 5/6 obligation. A locate gap blocks the next order; it does not excuse the disclosure owed on the position already held.
   • Decision point — ETFs and depositary receipts are not shares for Art. 12 (ESMA Q&A A4.6/A4.7), yet they do count towards the Arts. 5/6 position. Applying one rule's scope to the other blocks legitimate orders and misses real ones.

Full procedure: see references/workflows.md. Standards and citations: see references/standards.md. Printable pre-flight checklist: see assets/checklist.md.

Common Pitfalls

• Filing to a "15:30 CET" clock. The Art. 9(2) cut-off is 15:30 local time in the Member State of the relevant competent authority (ESMA Q&A A5.2, A9.3). For Finland, Greece, Cyprus, Bulgaria, Romania and the Baltics that is an hour earlier than CET — a scheduler pinned to CET files late every single time, and the breach is invisible because the job "succeeded".
• Rounding the percentage instead of truncating it. round(pct, 4) turns 0.49999% into 0.5% and demands a public disclosure that is not owed; it turns 0.09999% into 0.1% and generates a notification Art. 5(2) does not require. ESMA Q&A A5.6 is explicit: truncate to two decimals.
• Treating every recalculation as a new notification. Art. 5(2) triggers on reaching, exceeding or falling below a threshold. A position moving from 0.30% to 0.3989% owes nothing (A5.7). Re-filing on every tick floods the NCA and buries the crossings that matter.
• Forgetting that a fall is notifiable. Closing a 0.6% position to zero without notifying leaves a stale public disclosure standing on the register against your name.
• Netting raw share counts while holding options. The Arts. 5/6 position is delta-adjusted (DR 918/2012 Annex II Part 1). A book that is flat in shares and short 2% delta-adjusted through puts is a 2% net short position and is reportable.
• Letting a locate gap suppress the disclosure evaluation. The two regimes are independent. Returning "naked short ban breach" and stopping loses the public disclosure owed on the position you are already carrying — one breach silently becomes two.
• Applying Art. 12 to the wrong instruments. ETFs, ADRs and GDRs are not shares for Art. 12 (A4.6/A4.7); derivatives are not share sales at all. All of them still feed Arts. 5/6.
• Accepting an unevidenced locate. ITS 827/2012 Art. 7 requires the arrangement, confirmation and instruction in a durable medium, and ESMA has said that pointing at an "easy-to-borrow" list does not by itself satisfy Art. 6 of the ITS. A boolean flag with nothing behind it is not a locate.
• Assuming the whole EU regime applies to every EU-admitted share. Art. 16 takes third-country-principal-venue shares out of Arts. 5, 6 and 12 entirely.
• Reporting off a free-float or vendor share count. The denominator is total issued share capital across all classes including preference and non-voting shares (A6.6). A wrong denominator moves the whole position across bands.

Verification

• Instantiate EuShortSellingRegulationEngine(next_trading_day=next_weekday_excluding_holidays). For 100,000,000 issued shares and 600,000 net short (0.60%), expect reporting_status == "PUBLIC_DISCLOSURE_REQUIRED", disclosure_action == "NOTIFY_NCA_AND_DISCLOSE_PUBLICLY" and current_threshold_pct == 0.60.
• Submit 499,990 shares (0.49999%): expect net_short_percentage == 0.49 and PRIVATE_NCA_NOTIFICATION_REQUIRED — not a public disclosure. Submit 99,990 (0.09999%): expect BELOW_REPORTING_THRESHOLDS and NO_ACTION. Submit ESMA's own example, 319,900 (0.3199%): expect the filed figure 0.31.
• Submit 312,000 with previously_notified_percentage=0.30: expect NO_ACTION (still inside the notified band). Submit 50,000 with previously_notified_percentage=0.35: expect NOTIFY_NCA on the fall below. Submit 450,000 with previously_notified_percentage=0.55: expect NOTIFY_NCA_AND_DISCLOSE_PUBLICLY, because leaving the 0.5% regime updates the public register.
• Submit 800,000 with has_valid_locate_agreement=False: expect PUBLIC_DISCLOSURE_REQUIRED and art12_status == "NAKED_SHORT_BAN_BREACH" and is_short_execution_allowed is False — the coverage gap must not suppress the disclosure.
• Evaluate the same position with nca_timezone="Europe/Helsinki" and "Europe/Berlin": expect the two deadlines to differ by exactly one hour in UTC. Omit nca_timezone: expect notification_deadline_local is None and basis RCA_TIMEZONE_NOT_CONFIGURED, never a CET default.
• Gate a share order with covering_arrangement="NONE": expect blocked with NO_ART12_COVERING_ARRANGEMENT. With COVER_LOCATE_ARRANGEMENT and no locate_evidence_reference: expect NO_DURABLE_MEDIUM_EVIDENCE. Same order as an ETF: expect ART12_NOT_APPLICABLE and allowed.
• Run python -m unittest discover -s skills/eu-short-selling-regulation-disclosure-thresholds/scripts (71 tests) and confirm a 100% pass rate.

Related Skills

• eu-market-abuse-regulation-mar-surveillance
• us-reg-sho-short-sale-locate-requirements
• short-selling-borrow-cost-and-availability-modeling
• mifid-ii-algo-trading-compliance-eu
• record-retention-periods-by-jurisdiction