Order Types Market Order: A market order does not specify a price, it is executed at the best possible price available.  A market order can keep the customer from 'chasing' a market. Limit Order: The limit order is an order to buy or sell at a designated price.  Limit Orders to buy are placed below the current price while limit orders to sell are placed above the current price. Even thought you may see the market touch a limit price several times, this does not guarantee or earn the customer a fill at that price. In most instances, the market must trade BETTER than the limit price for the customer to get a fill.   Or Better: The pit broker is obligated to get the best possible price for the customer. Think of OB as a market order with a limit. If the price does not have an OB next to it, and the market is considerably better, the pit broker may question the runner to see if the order should have been a stop. They may return the order for clarification, which could delay execution and possibly change the results of the fill.   Market If Touched (MIT): Buy MITs are placed below the current price and Sell MITs are placed above the current price. An MIT order is similar to a limit order in that a specific price is placed on the order. However, an MIT order becomes a market order once the limit price is touched or passed through. An execution may be at, above, or below the originally specified price.   Stop Order: Stop orders can be used for three purposes: to minimize a loss on a long or short position to protect a profit on an existing long or short position, or to initiate a new long or short position. A buy stop order is placed above the current market and is elected only when the market trades at or above, or is bid at or above, the stop price.  A sell stop order is placed below the current market and is elected only when the market trades at or below, or is offered at or below, the stop price. Once the stop order is elected, the order is treated like a market order and will be filled at the best possible price.   Stop Limit Orders: A stop limit order lists two prices and is an attempt to gain more control over the price at which your stop is filled. The first part of the order is written like the above stop order. The second part of the order specifies a limit price. This indicates that once your stop is triggered, you do not wish to be filled beyond the limit price. Stop limit orders should usually not be used when trying to exit a position.   Stop Close Only: The stop price on a stop close only will only be triggered if the market touches the stop during the close of trading. The disadvantage of this order is a fast market in the last few minutes of trading may cause the order to be filled at an undesirable price. It can, however, protect the customer from getting filled during adverse price fluctuations during the course of the day.   Market On Opening (MOO): This is an order that the customer wishes to be executed during the opening range of trading at the best possible price obtainable within the opening range.   Market On Close (MOC): This is an order that will be filled during the final minutes of trading at whatever price is available.   Fill or Kill: A Fill or Kill order instructs the floor broker to buy or sell at your specified price and to immediately cancel the order if it is "unable" to be filled. One Cancels the Other (OCO): This is a combination of two orders written on one order ticket. This instructs the floor broker that once one side of the order is filled, the remaining side of the order should be canceled. By placing both instructions on one order, rather than two separate tickets, the customer eliminates the possibility of a double fill.