All or None Order (AON)

An order to buy or sell a quantity of assets at a predetermined price is known as an All or None order, or AON. An All or None order is placed with a clear direction as to how it should be filled, unlike other order types like a market order or limit order. An AON order must be filled entirely, as the name implies, or it cannot be filled at all. This stops orders from being partially filled and gives the buyer or seller the assurance that the execution price will remain constant for the entire amount. When a market exhibits significant levels of volatility with low volumes, such as during a flash crash type event, this type of orders can be utilized, for example, in algorithmic trading to determine the directional trend of a market and to prevent partial fill problems.