Methodology

This page documents exactly what our data is, where it comes from, and what we do to it. If anything here and a regulator's own documentation ever disagree, the regulator is right and we have a bug; tell us.

Sources

Every figure comes from an official regulator's public disclosure: the Financial Conduct Authority for the UK (next section) and ASIC for Australia (below). Nothing else feeds the site.

United Kingdom

The UK source is the FCA's public short-selling disclosures under the Short Selling Regulations 2025:

The daily ANSP publication, listing for each in-scope company: issuer name, ISIN of the main class of ordinary shares, the aggregate net short position as a percentage of issued share capital (the sum of individual notified positions of 0.2% or more), and the latest position date included.
The Reportable Shares List (RSL), the FCA's definition of which companies are in scope, updated monthly.

We hold no market-data licences by design: no share prices, market caps or volumes appear anywhere on this site, only regulatory position data.

Timing

The FCA publishes each working day at approximately 12:00 UK time, two working days after the position date (T+2). Our pipeline ingests at 12:30 UK with retries at 14:00 and 17:00. If a publication is missing all day, the site keeps the previous day's data and the homepage timestamp keeps showing the last real update, currently 10 Jul 2026.

Validation

Every downloaded file must pass validation before anything is published: the file parses; the row count is plausible against recent days; every ANSP value is within 0–100%; ISINs are well-formed; dates parse and are not in the future; no duplicate company/date rows. If any check fails we publish nothing and keep yesterday's data: accuracy over availability, always. Companies appearing in the publication but not on the RSL are kept and flagged, never silently dropped.

Corrections and revised figures

The FCA may exclude a notified position while verifying it and may amend or re-publish previously published aggregates. Corrections are a normal part of this dataset, and we treat them explicitly:

Every run re-reads a trailing window (10 working days) of publications.
When an already-archived figure changes, we adopt the new value and mark itʳ wherever it appears; the underlying data file records the old value, the new value, and the date we detected the change.
Our full data history is version-controlled, so every revision is auditable.

Derived numbers

Rankings, 1d/5d/20d changes, sparklines and the new & leaving lists are computed from the archived publications, nothing else. Changes are percentage-point moves measured across published trading days; companies with insufficient history show "–". Company URLs are stable slugs; a renamed issuer keeps its URL.

The legacy archive (pre-2026 register)

Before 13 July 2026 the UK published individually named short positions at the 0.5% threshold. We archived that register's final state (every current and historical disclosure back to 2012) before it was switched off. It powers the transition story and is kept frozen; it is not part of the daily dataset.Until the FCA's first ANSP publication on 13 July 2026, the figures on this site are a rehearsal dataset reconstructed from that archived register (summing named positions of 0.5%+ per company per day). They are shown to exercise and demonstrate the site, are labelled site-wide, and will be replaced by official ANSP data on day one of the new regime.

Australia

Australian data comes from ASIC's daily aggregated short position reports: for each ASX-quoted product, the short positions reported to ASIC by all short sellers (reporting obligations begin at A$100,000 or 0.01% of capital) as a percentage of total product in issue. ASIC publishes each trade date's file on the fourth business day after it (T+4); we ingest it the day it appears and never recompute ASIC's percentages. ASIC notes it cannot verify every individual report. The file covers all quoted products, occasionally including ETPs and quoted debt where reported positions can exceed 100% of a stub's units on issue.

What we are not

Independent site. Not affiliated with the FCA or ASIC. Nothing here is investment advice: we publish and explain regulatory data; we do not interpret it into recommendations, predictions or "signals". Internal operational notes: UK clock changes shift the FCA's publication time relative to UTC; our schedule is reviewed at each change.