AON vs. FOK: Understanding the Differences


When it comes to buying or selling stocks, different order types can significantly influence the outcome. One of the most common order types that traders use is “AON” (all or none) and “FOK” (fill or kill). These two strategies can help you control your trades, minimize risks, and maximize profits. In this blog post, we’ll dive into both AON and FOK to help you understand their differences and know when to use each of them.

AON (all or none) is an order type that requires the entire order to be executed, or none of it is executed. For instance, if you place an AON buy order for 500 shares, the broker will try to execute the complete order. If the broker can’t fill the whole order in one transaction, the process halts, and the unmatched portion of the order cancels. AON orders can be useful when you want to buy or sell securities in large quantities (e.g., more than 1000 shares) or if you have a specific price in mind. This strategy ensures that all of the orders are completed, which reduces the risk of partial fills.

In contrast, FOK (fill or kill) is a type of order that must be executed immediately in its entirety, or it will be canceled. If the broker can’t find enough shares to complete the order, then the entire order is canceled. FOK orders can be useful when you don’t want to take any risks and need to enter or exit a position quickly. For example, if you place a FOK sell order for 100 shares, the broker will try to fill the entire order in one transaction; if they can’t, they will immediately cancel it. This way, you won’t have to worry about being left with a partial fill.

AON vs FOK: The Differences

One of the main differences between AON and FOK orders is that FOK is a more extreme version of AON. With that being said, traders should choose when to use each type depending on their investment goals and trading strategies. If a trader is willing to accept a partial fill, they should use AON. But if they do not want a partial fill, FOK is the better choice.

Another difference between AON and FOK is their impact on price movements. FOK orders can have more impact on prices as they require immediate fills of all shares before they are canceled. Thus, it’s best to use FOK orders when you want to enter or exit a position quickly without significantly affecting the market price. In contrast, AON orders may not have a significant impact on price movements if they don’t get filled.

Lastly, it is worth noting that both AON and FOK orders may come with additional fees charged by brokers. As these orders require a more sophisticated execution, brokerage firms may charge additional fees ranging from a few cents to a few dollars depending on the order size and the broker’s commission level.


In summary, understanding the differences between AON and FOK orders is crucial for traders looking to minimize risks and maximize profits. While both strategies can be useful for different trading scenarios, traders should weigh the pros and cons of using each strategy before deciding which order to use. As always, it’s essential to have a sound trading strategy and to use risk management techniques to avoid significant losses. By incorporating AON and FOK orders into your trading plan, you can stay one step ahead of the competition and make the most out of your trades.