Changes to the ASX Opening and Closing Phases

Please note the following changes introduced by the Australian Securities Exchange (ASX) as part of Service Release 15 (SR15) will take effect on Monday, 23 June 2025.

Two key changes being introduced from 23 June 2025 include:

Removal of the Opening Auction Stagger

  • The staggered opening times for 5 groups of stocks will be removed.
  • All stocks open randomly between 9:59:00am and 9:59:15am.
  • Continuous trading starts between 9:59:45am and 10:00:00am.
  • A session called Open Single Price Auction (OSPA) will last 30-60 seconds, starting at 9:59:00am (+15 seconds). During this session you will only be able to cancel orders as per exchange rules.

Watch this ASX video for more information on the Opening Auction Stagger changes.


Post Close Trading Session

  • After the Closing Single Price Auction (CSPA), there will be a 10-minute and 30-second trading period.
  • During this period, any remaining volume left over at the match price may trade.

Please note all market-related times listed above are based on Sydney time.


For more information and other enhancements the ASX are introducing, please contact the ASX Support Centre on 131 279.

Updated: 17 June 2025

Published: 16 June 2025

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