when a limit order is entered into a trading system and fielded by either a specialist working the book or an electronic database of orders it will stay on the books until it can be matched with a suitable trade and executed buy limit orders are placed with an upper price threshold the investor would say i don t want to pay more than x for this share sell limit orders are placed with a lower price threshold the investor would say i don t want to sell this share for less than x 
limit order qualifiersa limit order may include qualifiers without qualifiers on an order the request will be valid only for the market day considered a day order and may expire without any purchase or with only a partial fulfillment of shares if an investor s order states buy 10 000 shares of xyz common 32 they have requested to buy 10 000 shares at 32 or a better price the qualifier for this order if the investor s strategy requires 10 000 to be filled at any time at the requested price or better it may be entered as buy 10 000 shares xyz 32 gtc a good til cancelled order instructs the market to acquire those shares until the order is canceled even if the purchase is completed 100 shares at a time and over several weeks the investor wants the order completed regardless of how long the market takes to fill the order another qualifier is the aon or all of none investors may not want to risk only partially completing the order so they use this qualifier to instruct the market to fill this order with all 10 000 shares as requested or buy none there are other types of order qualifiers that allow an investor to ensure the transaction is executed exactly in the manner that suits their particular investment objective and in each case define the limits the investor is putting on the market to make the trade special considerationsinvestors are guaranteed to get the price if the order is triggered after the market moves to the specified level however there is no guarantee that the limit order will be executed in other words the order can only be filled if the price hits the price level limit orders are helpful to investors because they help ensure that they don t pay more for a security than the pre set price initially established with the order 