Stop/Loss
The Stop/Loss is probably the most important value that should be set in a pending order or a open position. With the Stop/Loss you specify when to shut the reach of commercial value automatically. If you forget to set the Stop/Loss, and the price will rise or fall against its trading direction into the abyss, you lose within your response time always more than you have planned for this trade as a loss limit.
Read our article about the trailing stop.