Data methodology
How ShortInterest.au builds ASX short interest pages
ShortInterest.au turns public short-selling reports into searchable tables, ticker pages, and charts. The goal is to make the source data easier to inspect without hiding the reporting lag, definitions, or limitations.
Last reviewed: 2026-05-31
Primary sources
ASIC short position reports and ASX gross short-sales notices are the core inputs.
Clear lag labels
T+4 and T+1 labels are shown next to dates so the timing is visible before interpretation.
Quality checks
Ingestion checks look for missing files, empty rows, malformed tickers, and stale publication dates.
Sources
The main series on this site is derived from ASIC short position reports. ASIC receives reported short positions and publishes a public table of files, which ShortInterest.au converts into ticker histories and leaderboards.
What each metric means
ASIC short interest (T+4)
This is the outstanding short position reported to ASIC, shown as a percent of shares on issue where the source data supports that comparison. It is useful for comparing how heavily different ASX securities are shorted, but it is delayed by the regulatory reporting cycle.
ASX gross short sales (% capital, T+1)
This is a daily flow measure from ASX gross short sales reports. It reflects reported short-selling activity for a trading session, not the stock of open short positions. It can move before the ASIC T+4 position series updates.
7-day and 30-day changes
Changes are shown in percentage points, not percent change. For example, a move from 2.00% short to 2.50% short is displayed as +0.50 percentage points.
Update cadence and checks
ShortInterest.au checks for new source files on business days. Pages are cached for performance and refreshed when the data pipeline confirms a new file has been processed. During source outages or API interruptions, the site keeps educational pages online and labels data availability instead of pretending the feed is current.
Automated checks cover file retrieval, row parsing, ticker casing, duplicate rows, empty reports, and the latest processed date. When a source file is amended or a processing issue is found, we correct the derived pages after the source has been reprocessed.
Limitations
Short interest is not a complete investment thesis and should not be treated as a buy or sell signal. It can reflect hedging, arbitrage, index activity, reporting lag, or company-specific events. Always review original filings and consider professional advice before making financial decisions.
Corrections and questions
If you believe a ticker page has stale, missing, or incorrect data, send the ASX code, date, and issue description through the contact page. We review corrections against the source files before updating the site.