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Australian Securities Exchange (ASX)

The ASX is the primary equities exchange in Australia.

Currency: Australian Dollar (AUD)

Trading Hours & Calendar

Trading Summary

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

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

Available ATS

Basic Market Rules

  • Lot Size - minimum lot size = 1; maximum lot size = 999,000,000
  • Tick Size - the tick size varies by price as follows:
Price Range Tick Size
Up to 10c 0.1c
10c up to $2.00 0.5c
$2.00 up to $99,999,999.00 1c
  • 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 10:00AM and lasts for about 10 minutes. The reason for this is that stocks are divided into 5 groups which open sequentially as follows:

  • Group 1 (A-B) 10:00:00AM +/- 15 sec
  • Group 2 (C-F) 10:02:15AM +/- 15 sec
  • Group 3 (G-M) 10:04:30AM +/- 15 sec
  • Group 4 (N-R) 10:06:45AM +/- 15 sec
  • Group 5 (S-Z) 10:09:00AM +/- 15 sec

For a detailed description of how the opening price is calculated, see here.


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 sub-paragraph a);
  • c) The pairing and re-establishment of priority set out in paragraphs a) and b) is 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 paragraph 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 (16:10-16:12 - random time +/- 30 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.

For more information on the auction mechanisms on the Australian Stock Exchange, please see here, Appendices

Additional Info

Here you can find a number of third-party reference sources to help you learn more about the Australian equities markets.

Financial News/Research

Market Data

See Also


asx.txt · Last modified: 2016/05/10 16:58 (external edit)