All or None (AON) Order

An All or None (AON) order is an instruction to execute a trade only if the entire specified quantity can be filled — no partial executions are accepted. Unlike a Fill or Kill order (which requires immediate complete execution), an AON order can remain open and wait for sufficient liquidity to fill the complete order quantity. If the full quantity is not available at the moment, the order stays in the queue rather than being cancelled. AON orders are used when partial fills would leave an investor with an unworkably small or unbalanced position — for example, when executing a minimum block size requirement or ensuring a specific lot quantity for a derivatives strategy. They are more common in bond and OTC markets than on Indian equity exchanges.