There are some important changes to be aware of regarding the ASX's opening and closing trade times, effective today (23 June 2025).
Market Open
From today, the ASX has moved to single open, with all stocks opening for trade at the same time, at around 10:00am (AEDT).
Previously, the ASX has operated a staggered opening auction with five batches of shares. The first batch (companies with stock codes starting with A-B) opened at approximately 10:00am, while the fifth batch (companies with ticker codes beginning with S-Z) typically didn't open for trade until approximately 10:09am. It has been operated this way since the beginning of electronic share trading in 1987, mostly to allow for a more controlled opening of the market. However, the ASX is one of the only (if not the only) exchanges to have operated this way.
Thanks to modern technology, the ASX no longer needs to stagger the opening. All shares will now go through an opening auction at around 9:59am, and normal trade will begin by 10:00am for all companies.
Key point: From today, all stocks will start trading at the same time – around 10:00am AEDT.
Source: ASX
Market Close
The ASX still closes at 4:00pm AEDT for normal trading.
Until now, the ASX has remained open until 4:00pm AEDT, with the Closing Single Price Auction (CSPA – the closing price for the day for any given security) taking place between 4:10pm and 4:11pm.
From today, the market will run a short closing auction between 4:00pm and ~4:10pm to determine the official close price for each stock at the end of the session. No trades go through at this time, though you might see prices adjust as this auction happens in the background. The closing price for each stock will then be determined at approximately 4:10pm.
There will then be a post-close trading session, from 4:12pm to 4:20pm, which will be mostly for filling the large orders of institutional or professional traders etc (the closing auction is an important period for many professional and institutional investors, many of which need to match the session's closing price as closely as possible). Notably, most retail investors cannot access this session.
Key point: Ordinary investors will generally need to place your orders before 4:00pm to have them filled on the same day. Any orders entered after 4:00pm will almost always wait until the next trading day to be executed.