What Is All Or None (AON)?

All or none (AON) is a common type of contingent order that specifies the entire size of the order must be filled and that partial fills will not be accepted. AON orders thus involve a directive used on a buy or sell order that instructs the broker to fill the order completely or not at all. If there are too few shares available to fill the order entirely, the order is canceled.

Key Takeaways

  • All or none (AON) is an order type with the instruction to fill the order completely or cancel it; partial fills are not allowed.
  • AON orders usually take longer to execute than normal orders, especially for larger order sizes.
  • Preventing partial fills is particularly useful when transacting with thinly traded securities or when a hedge requires a specific order size.

Understanding All Or None Orders

An AON order is considered a contingent order because the trader gives instructions to the broker regarding how the order has to be filled, which affects how long the order remains active. AON orders that cannot be executed at the time of submission remain active during trading hours until they are filled or canceled. This prevents partial fills, which is particularly useful when transacting with thinly traded securities.

One major drawback is that, since these orders have specifications, they can take longer to execute than normal orders. A fill or kill (FOK) order is one that combines all or none and immediate or cancel (IOC). A FOK order is thus an AOC order with a very limited duration.

Larger AON orders or those in illiquid markets, however, are often more difficult to fill, because the order composes a greater percentage of the number of shares traded daily


Suppose an investor places an AON order to purchase 200 shares of Microsoft common stock at $100 per share, which means the order is not to be filled unless all 200 shares are purchased at $100. The investor has specified both the number of shares and the price required to fill the order. Two hundred shares is a trivial number of shares to purchase when compared with the daily trading volume of Microsoft stock, so it is likely the order will be completed if the shares trade at $100 during the day.

Note that while Microsoft may trade at $100 a share, it would be more difficult to purchase 100,000 shares at $100 using an AON order than it would be to buy 200 shares.

Factoring in Technical Analysis with AON Orders

Many portfolio managers use technical analysis, defined as the scrutiny of stock price patterns and trading volume, which may necessitate using an AON order to enter or exit the market. When a stock price trades above or below a range of trading, the price may indicate a future trend. Suppose, for instance, that a stock trades between $20 and $25 per share for several weeks, but then rises to $27. Technical analysts call this trading pattern a breakout, meaning the share price continues to climb. A portfolio manager can place an AON order, which requires the entire order to be bought at the $27 breakout price, thereby allowing the manager to generate profit from the upturn in price.

Using Fundamental Analysis with AON Orders

Portfolio managers also use fundamental analysis, which can be defined as a study of a company's financial statements and financial ratios. Managers compare the financials of a company to a similar business in the same industry, which can often aid their decision to either buy or sell that company's stock. As they do with technical analysis, portfolio managers use AON orders to buy and sell stocks based on fundamental analysis.

Assume, for instance, that the price-to-earnings (P/E) ratio for the overall technology sector is 30 times earnings, and that Microsoft's P/E ratio is 20x ($100 stock price / $5 earnings). Microsoft's lower P/E ratio means that the company is generating more earnings per share, which makes the stock's price more attractive than other firms in the industry. Therefore, the manager uses an AON order to buy 5,000 shares of Microsoft at $100 per share since its P/E ratio indicates a buy signal.