What is the ASX Anomalous Order Threshold (AOT)?

To ensure a fair and orderly market, the ASX is required to set an acceptable price range for all securities. If an investor tries to place an order that falls outside of this price range, the ASX is required to reject the order.

The price range is known as an Anomalous Order Threshold (AOT). The AOT price is dynamic, and it’s updated continuously throughout the trading day. When an investor enters an order that breaches the ASX AOT price the order will be cancelled.

Why do the ASX AOT rules exist?

The reputation of the Australian sharemarket is important for the Australian economy as a whole. Market participants like the ASX and Chi-X are required to have rules in place to ensure fair and orderly trading occurs – to protect investors, and to maintain the integrity of the entire market.

What should I do if my order is rejected because of the ASX AOT rules?

  • If you tried to place a Limit Order and it was rejected, you can try placing a new order with a less aggressive limit price.
  • If you tried to place a Market Order, you can try placing a Limit Order instead.



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