Trailing Stop — is an algorithm of a Stop Loss order level managing.
If you place a Trailing Stop (for X pips) the following will happen:
MetaTrader doesn't do anything until the profit of an open position reaches X pips. Then MetaTrader places a Stop Loss order at the distance of X pips from the current price (at the breakeven point in this case).
Once the first step is completed MetaTrader sends a command to modify the level of the Stop Loss order by the distance of X pips from the current quote every time when the distance between the quote and the previous order's level exceeds X pips. As a result the Stop Loss order «catches up» the current price.
In order to place Trailing Stop highlight the necessary open position in the «Trade» tab in the «Terminal» window and press the right mouse button. In the appeared context menu you can set Trailing Stop level.
Trailing Stop placing
In order to place the pending order in the «New Order» window change the type to the «Pending order».
Trailing Stop — is one of the most effective instruments of maximizing profit. If you determine the value of Trailing Stop correctly you won't close out earlier than the price movement in your direction finishes. Trailing Stop can significantly increase profitability of your trading practice.
You should start MetaTrader and connect it to the Internet to make Traling Stop work.