An All-Or-None (AON) order is an instruction that requires the full quantity to be filled before it is considered executed. If a venue cannot provide the full amount, the order remains unfilled and may be canceled when the chosen time-in-force expires. This differs from standard orders that may be partially filled. AON orders are commonly used for large block trades or in markets with shallow liquidity, where partial fills could leave the investor with an unwelcome residual position.
AON can be specified on certain order types and time-in-force choices. Because execution depends on a counterparty offering the full quantity at an acceptable price, AON orders can take longer to fill and may have a higher risk of no execution in thinly traded securities. Traders consider whether avoiding partial fills justifies potentially longer wait times or no fill at all.
In practice, AON interacts with liquidity provision, routing decisions, and venue rules. It is distinct from other conditional orders such as Fill-or-Kill (FOK), which requires immediate all-or-nothing execution, and Immediate-or-Cancel (IOC), which allows immediate partial fills with the remainder canceled. Time-in-force settings and broker handling of large blocks and dark pools influence whether an AON order can be completed.
An investor places an All-Or-None order to acquire 50,000 shares of a thinly traded stock; the order will only execute if the entire 50,000-share quantity can be filled, otherwise it is canceled at the end of the time-in-force.
Fill-or-Kill (FOK) Order · Immediate-or-Cancel (IOC) Order · Limit Order · Partial Fill · Time in Force · Block Trade · Liquidity