Data sources
ASIC T+4 vs ASX T+1 short-selling data
Understand the difference between ASIC short positions and ASX gross short sales, including timing, meaning, and common interpretation mistakes.
Last reviewed: 2026-05-31
The two feeds answer different questions
ASIC short-position reports are the main short-interest series on ShortInterest.au. They describe outstanding short positions reported for a trade date and are published with a T+4 lag. This is the better source when you want to know how much short exposure remains open.
ASX gross short-sales data is different. It is a next-day flow measure that describes short-selling activity for a trading session. It can be useful as an early sign of activity, but it is not a direct substitute for the ASIC outstanding-position number.
Side-by-side
| Question | ASIC T+4 | ASX T+1 |
|---|---|---|
| What is it? | Outstanding short position | Daily gross short-sales flow |
| Timing | Trade date plus four business days | Next business day |
| Best use | Positioning level and trend | Recent session activity |
| Common mistake | Treating it as live data | Treating flow as open interest |
Why a T+1 spike may not appear in T+4 positions
A large gross short-sales day can be followed by covering, paired trades, market-maker activity, or other transactions that reduce the final open position. That is why the ASX series can move sharply without the ASIC series later showing an equal change.
The reverse can also happen. ASIC positions can keep rising even when the latest ASX gross short-sales print looks modest, because the outstanding position reflects the cumulative balance of additions and covering across multiple sessions.
How ShortInterest.au labels the data
Pages label the source date and lag next to the metric. The site uses ASIC T+4 for the main % short level, the leaderboard, ticker charts, and 52-week ranges. Where ASX gross short sales are shown, they are labelled as T+1 gross flow and described as a different measure.
This separation is intentional. It lets readers use the faster ASX signal for context while keeping the core short-interest analysis tied to the outstanding-position series.
For the site's full data handling notes, read the methodology.