As is commonly known, there are two major orders that can be made before an action buy and sell. Like almost everything in the market they are bought and sold by investors. Here you could get some ideas. But investing is not always as basic as buy and sell at the price current at the time but can bring in some situation from which our order to buy or sell is executed.
We mark a maximum and minimum price that our order will be executed. To purchase just action will be purchased at the highest price we have set or a lower price. For sale, only our share will be sold at the minimum price or that have set a higher price. Thus, might the whole order is not executed right away, as you may have to wait for the required price range, but we make sure get the price we want.
Any price limit is not set so the order will be executed at the best price existing at that time in the market, so that: For the purchase they will be purchased all shares that wish to bid lower rate, that market at that time. For sale they are sold all shares that desire, the maximum price they are offered on the market at that time. In this way, we ensure that our order will be executed almost instantaneously, but in return we risk not being able to control the price in any way, since our order is executed at the best price which exist at this time, although this will varying.
Order at best
In this type, the investor does not state a limit of purchase price but the whole order is fixed to the price at which they sell / buy the first action. In this way: For purchase if our order includes 100 shares and only 50 can play at the best buy price at that time, the remaining 50 will be on hold until they can run at the same price as the others. For sale the same applies in reverse. If we want to sell 100 shares, but only 50 can be executed at the best price to sell, the rest will remain on hold until they can be sold at the same price. So, we get a balance between being able to sell more or less rapidly the actions, and to have some control over the price.