1. When does the ASX open and close?
The ASX trading day consists of several sessions designed to facilitate efficient price discovery and orderly trading. The regular trading hours for the Australian stock market are from 10:00 AM to 4:00 PM (AEST) on trading days Monday to Friday, excluding public holidays. Due to the design of the opening auction, the market may open as early as 9:59:45 AM.
Below is a summary of the key sessions and timings:
• Pre-open Session (7:00 AM – 9:59 AM): Clients can enter, amend, or cancel orders. All orders will be queued in the exchange. No trades are executed during this period.
• Opening Single Price Auction (OSPA) (9:59 AM – 10:00 AM): The opening auction determines the market’s opening price. Its start and end times are randomised within a short window, with the earliest possible start at 9:59:00 AM. During this period, only order cancellations are permitted; new orders and amendments are not allowed.
• Continuous Trading Session (10:00AM – 4:00 PM): Continuous trading begins immediately after OSPA ends, with the earliest possible start at 9:59:45 AM. During this period, clients can enter, amend, or cancel orders, and trades are executed continuously.
• Pre-Closing Single Price Auction (Pre-CSPA) (4:00 PM – 4:10 PM): Clients can enter, amend, or cancel orders in preparation for the closing auction. All orders will be queued in the exchange. No trades are executed during this period.
• Closing Single Price Auction (CSPA) (4:10:00 PM – 4:11:00 PM): A randomised 30-second auction determines the official closing price. Only order cancellations and trade reporting are allowed during this window.
• Post Close Trading Session (4:11:00 PM – 4:21:30 PM) Unmatched auction orders will be carried forward into this session, where orders can only be executed at the closing price determined by CSPA. Only order cancellations are allowed during this window.
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