Example: You want to buy 5000 shares in a stock, but only if its price climbs to 60 Swiss francs per share from its current 57 francs per share. You do not have a limit on how much you are willing to spend on the shares (or you would use a stop limit + trailing stop order). If and when you have bought the shares, you want to hold them for as long as their price continues to go up, and sell them if the stock’s price falls by 5%.
Using a stop + trailing stop order, you can select a buy stop limit (in this case 60 francs) so that the broker only buys the stock if its price increases past the selected threshold. You can also instruct the broker to hold the shares and only sell them if their price drops by a certain percentage or monetary amount from its position at any point in time thanks to the trailing stop order.
So stop + trailing stop orders let you select the conditions under which you want assets to be bought and then sold before you make the investment. Stop limit + trailing stop orders give you even more control than stop + trailing stop orders because they let you specify the maximum amount which you are will to pay for assets. But stop + trailing stop orders have the benefit that you can be sure assets will be bought. In the case of stop limit + trailing stop orders, assets will not be bought if the broker cannot buy them at or below the buy limit.