In an attempt to facilitate a reasonable and well-structured market, the ASX sets designated price ranges for all securities. If a retail investor makes an attempt to place an order that falls outside the parameters of this range, the ASX has the ability to reject this order. You will have the ability to place another order which is more aligned with the current price of the security. 

The spread of this price range is known as the Anomalous Order Threshold (‘AOT’). The AOT price for any given security is not concrete and fluctuates constantly throughout the respective trading day.