It is an artificial order, which consists of two things: a limit order (see) and a stop order (see). Here is an example. You expect that the price will go up, and then turn around and go down. You order the broker to open a position to sell at a higher price (to which you think the price will reach and turn around). The broker marks your order as limited, deferred. But this type of order is a special one: it can not be executed. After all, even when the price reaches your level, there may not be enough demand. That is, at this price no one wants to buy. Here the stop order shows the broker on a compulsory basis that your position should be open. In this case, your transaction has established the price they are now offering on the market. However, it may be lower than you expected. However, on a dynamic market, liquidity (see), this difference will be only a few points.