Limiting your forex trading orders is of great importance because it helps you fix your profit before losing it. It also helps you to limit as well as control your greed. During forex trading, it is better to maintain a trade as long as it is headed in a favorable direction and there are no chances of it reversing, but you can still set a limit that will help you control the profit. It should not worry you if the price keeps on heading in the same direction even for a couple pips after reaching your limit. That will imply that you are already out of the game.