This is a tool designed to help minimise losses and save at least part of earned profits. If you're already in plus by, say, 30 points, the system will automatically move your stop-loss (see) in a "positive support" zone, following the price so that you always have a guaranteed income from the transaction. The more the price goes into positive, the more that will be exposed by the trailing stop. If the profitability of the position decreases, the trailing stop stays in place and does not move anywhere. To set a trailing stop, you must first open a transaction and then in the window below the graph in your terminal click on the line with the transaction, right-click, choose "Trailing Stop" and set to the desired level. For example, if you select the level to 15 points, then every time the price will move in the desired direction, then the trailing stop will move behind it at a distance of 15 points.