All or none
Family XII · Other terms
Not to be confused with market order, limit order, partial fill.
All or none (AON) is an order condition that requires the full stated quantity to be executed at once. If the market cannot supply the complete size in one trade, the order is rejected or cancelled rather than partially filled. The condition is set by the trader and is separate from the order's price instruction.
How it works
An all-or-none instruction is attached to an order before it is sent to a market or venue. The matching system checks whether the full quantity is available at the specified price or better. If it is, the trade executes for the entire amount. If not, the order does not execute at all.
This differs from a standard order, which can be filled in parts. AON orders are common when a partial fill would be impractical or when the trader needs the complete position for a related transaction.
Worked example
Variations and venue rules
Whether an all-or-none order is accepted, and how it interacts with other order types, depends on the rules of the exchange or venue. Some markets do not support AON conditions, while others apply them only to certain order types or sizes. Traders should check the specific venue's order handling rules before relying on an AON instruction.
Often confused with
- market order
- A market order is an instruction to buy or sell a financial instrument immediately at the best available current price, without specifying a price limit, so execution is prioritised over price certainty.
- limit order
- A limit order is an instruction to buy or sell a specified quantity of an instrument only at a stated price or better, and it may remain unfilled if the market never reaches that price.
- partial fill
- A partial fill is the execution of only part of an order's requested quantity, leaving the remainder unfilled and, depending on the order type, either resting in the book or cancelled.