Stop loss is a widely used order aiming mainly at limiting the possible losses in case of negative market movements.
Stop loss is used only with open positions. When the market conditions are not favorable for a trader and the price has reached the level of Stop loss, the deal is closed automatically. Therefore, Stop loss helps the trader to control losses and in case of failures to keep safe at least the part of the deposit.
If a trader does not use Stop loss orders, the position is closed by the broker when the sum of losses is equal to the sum of the deposit.
There are 3 types of Stop loss orders: fixed Stop loss, sliding Stop loss and combined Stop loss.
Fixed Stop losses are set while opening positions. They cannot be replaced until the deal is closed. Sliding stop losses, on the contrary, can be replaced any time depending on the price movement. Another name for sliding Stop loss is Trailing stop that can be replaced either manually or automatically considering the traders settings.
Presently there are lots of discussions on whether it is necessary to use Stop losses or not. Some traders believe that Stop loss should be compulsory for trading, emphasizing the ability of Stop losses to prevent the loss of the whole deposit. If the price is rapidly moving in direction, which does not correspond to the forecast, the deal that has not been closed in due time can result in significant losses. The opponents of Stop loss believe that this order can limit not only losses, but profits as well. As the price movement is often unpredictable and unexpected, it can develop according to the traderís expectations though with some periodic bounces crossing the Stop loss line. In this case the position is closed with losses though it was a possible to close it with profit.
As a rule, the decision on whether to use Stop loss or not depends on the individual strategy of a particular trader. Therefore, there is no single opinion on the necessity of using the limiting the losses.