All or none (AON) is a finance term used in investment banking or securities transactions that refers to "an order to buy or sell a stock that must be executed in its entirety, or not executed at all".
AON orders are similar to fill or kill (FOK) orders, but the former focuses on "complete vs. partial fulfillment", whereas the latter hinges on the immediacy of the transaction.
[3] Price inflation is the main disadvantage of AON orders.
[4] Continuing with the previous example, let's say that three months later, your broker informs you that all 100 shares of JKL Co. are now available for purchase, but the stock price doubled from $2 to $4.
Since you did not cancel this AON order, you are then forced to buy all the 100 shares of JKL Co. at double the price you intended.