This is an order to the broker (see) to make a deal to buy or sell an tool at a specified price, which is lower than the current one. hat is, if we are talking about an order to buy (Buy-stop), the price specified in the order (see) will be higher than the current. If we are talking about the transaction price, the price specified in the order, will be lower than the present. For example, you open a deal to sell off the mark 5 and the price is reduced. However you want secure against potential losses and assume that if the price does not meet your expectations, turn around and come up to the mark 8, it will continue to grow further. So you decide to put a stop order to buy from this level. That is if the price comes up to it, it opens your transaction for the purchase and you start earning. Note that this is a very dangerous type of order, because as a rule, the price only slightly touches the buy-stop or sell-stop line, the transaction opens and then the price turns around and the trader starts to lose money rapidly.