The time it takes to receive a confirmation after an order has been placed varies depending on the type of order placed, the liquidity of the market being traded and whether a market is open or not.

Orders placed between 9:30 a.m. and 4:00 p.m. Eastern Standard Time Monday to Friday on the New York Stock Exchange or Nasdaq are sent to the market right away. Unless specifying that an order is an extended market order, orders placed outside these times sit until the market reopens.

A market order in a liquid stock such as Apple Computer (AAPL) or Facebook (FB) is almost always filled and confirmed immediately.

Stock Orders That May Take Longer to Fill

Orders with conditions such as limits, stop-losses, stop-buys and all-or-nothing may sit for an indeterminable amount of time before being filled, or it may never be filled at all. Market orders for large amounts of stock in thinly traded markets may receive several partial fills over a period of time, which varies depending on the amount of stock available.

It is always advisable to buy or sell using limit orders, even if the limit is 20 or 30 cents above the market price (for a buy order) to ensure the receipt of a fair fill. There are instances when liquidity may disappear (even in shares such as AAPL or FB) for a short time period, causing investors to get filled with market orders at a much higher or lower price than expected. Orders for large amounts of stock should either be broken up or made using limit orders.

How to Know When a Trade Placed With a Broker Is Confirmed

When placing a trade with a broker online or over the telephone, ensure the trade has been executed and confirmed. 

Online brokers have different trading platforms. Most have an order entry screen and a screen for orders of different statuses: open, filled, partially filled and cancelled. After entering an order, view these screens to ensure the intended action is taken. If you want to cancel an order, check the screen for canceled orders and open orders to ensure that the original order was actually canceled. Make sure it is reflected in the canceled order screen as well.

When investing over the telephone, get a verbal confirmation from the broker on the quantity filled and the price. With these details, you can be confident that your broker has carried out your wishes. A few days after you have made the trade over the telephone, you should receive a confirmation in the mail from your broker. Ensure that the details of this confirmation match your intentions. Usually, trades made over the telephone are visible on the company's website or trading platform as well, so you can confirm them immediately.