What is all or none (AON) order?
An all or none (AON) order is a trading order that must be executed in full at a specified price, or not executed at all. If the full quantity cannot be filled, the order will remain unfilled or be cancelled.
In simple terms, it tells your broker: “fill the entire order, or do nothing.”
How an all or none order works
When you place an AON order, the system checks whether enough shares or contracts are available at your chosen price to complete the trade.
Unlike standard market or limit orders, partial fills are not allowed.
Because of this restriction, AON orders may take longer to execute, especially in markets with lower liquidity or limited trading activity.
Example of an AON order
Imagine you want to buy 1,000 shares at $20 using an all or none order:
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Only 600 shares are available → the order is not executed
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Later, 1,000 shares become available → the full order is filled
If the full quantity never becomes available, the trade will not go through at all.
Advantages and disadvantages
Pros
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Ensures your full position size is executed
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Avoids partial fills and inconsistent pricing
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Provides better control over trade execution
Cons
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May not be executed at all
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Can take longer to fill compared to standard orders
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Less suitable in fast-moving or highly liquid markets
AON orders prioritise certainty over speed, which can increase the risk of missing trading opportunities.
When do traders use AON orders?
Traders typically use AON orders when precision matters more than speed, such as:
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Building a position with an exact size
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Trading large volumes where partial fills affect strategy
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Reducing multiple transaction costs from split trades
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Entering positions in less liquid markets
They are commonly used by more experienced or institutional traders who rely on accurate position sizing and controlled execution.
Risk Warning: Trading CFDs involves significant risk and may not be suitable for all investors. Losses can exceed your initial deposit. Please ensure you fully understand the risks involved before trading.
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