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Australian Securities Exchange (ASX)

The Australian Securities Exchange is Australia's primary securities exchange, sometimes referred to outside of Australia as the Sydney Stock Exchange. ASX is home to some of the world’s leading resource, finance, and technology companies.


Currency: Australian Dollar (AUD)

Holiday Calendar
Trading Hours

Trading Summary

The ASX has opened up to competition in recent years, with the notable entry of Chi-X in execution venues.

For more information about the ASX, see the Corporate Overview page.

Lit Order Types

  • Limit Buy/Sell→ShortSell

  • Market Buy/Sell→ShortSell

  • Market-on-Close Buy/Sell→ShortSell

Dark Order Types

  • Limit Buy/Sell→ShortSell

  • Market Buy/Sell→ShortSell

  • Midpoint Pegged Buy/Sell→ShortSell

Basic Market Rules

  • Lot Size: min. 1; max. 999,000,000

  • Tick Size: varies by price, as follows:

Price RangeTick Size

Up to 10c0.1c

10c up to $2.000.5c

$2.00 up to $99,999,999.001c

  • Short Sale Rules: short sales must be declared and are only permitted where a locate for the shares has been obtained. Naked short selling is prohibited.

  • Circuit Breakers: although the ASX has not established fixed thresholds for circuit breakers or trading halts, trading in a company's shares may be halted from time to time for market-sensitive announcements or at the request of the company.

Auction Mechanisms


The opening auction procedure begins at 10:00 AM and lasts for about 10 minutes. Opening prices are calculated during this phase. Securities open in five groups, according to the starting letter of their ASX code:

  • Group 1 10:00:00 am +/- 15 secs 0-9 and A-B, e.g. ANZ, BHP

  • Group 2 10:02:15 am +/- 15 secs C-F, e.g. CPU, FXJ

  • Group 3 10:04:30 am +/- 15 secs G-M, e.g. GPT

  • Group 4 10:06:45 am +/- 15 secs N-R, e.g. QAN

  • Group 5 10:09:00 am +/- 15 secs S-Z, e.g. TLS


The closing price is defined by the following closing auction mechanism.

Auction means an auction conducted in a Trading Platform in respect of Qualifying Bids or Offers pursuant to the following process:

  • a) The Priority Bid is paired with the Priority Offer so that either the Bid or the Offer is fully satisfied;

  • b) A new priority of Bids and Offers is established, deducting the quantity of Products paired under point a);

  • c) The pairing and re-establishment of priority set out in point a) and b) are repeated until the Priority Bid is below the Priority Offer;

  • d) All paired Bids and Offers are then matched at the Equilibrium Price;

  • e) Any Bids or Offers which have not been matched at the completion of the process described in point b) will be carried through to the next Session State

Auction Periods

1. Pre-CSPA (16:00 - 16:10): During this period:

  • Bids and Offers may be entered, amended, or cancelled in the Trading Platform

  • Bids and Offers remaining in the Trading Platform from the previous Session State may be amended or cancelled

  • Bids and Offers remaining in the Trading Platform at the commencement of the Session State retain their ranking in Price/Time Priority

  • No Bids or Offers will be matched

  • Allowable trades may be reported

2. CSPA (Closing Single Price Auction) (16:10-16:12 - random time +/- 60 seconds): During this period:

  • An Auction is conducted on commencement of the Session State

  • Auction Imbalance Orders are matched with other Orders at the end of the Auction following the transition of the Pre-CSPA Session State to the CSPA Session State

  • No Bids and Offers may be entered, amended, or cancelled in the Trading Platform

  • Qualifying Bids and Offers that have not been matched in the Auction will be carried through to the next Session State in Price/Time Priority

  • No trades may be reported

Order Types: traders can enter Limit, Market, and Market-on-Close orders to participate in the auction.

Additional Info

Financial News/Research


Market Data

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