Answer and Explanation:
Margin trades work this way because they allow them to extend the amount of money invested regardless of whether the security's price drops or rises. In a more simplified way, we can state that the margin trade allows that even if the price of a security goes up or down, the invested money presents a percentage of gain or loss much bigger than the original value. This is because this money was deposited as a loan guarantee, allowing interest to run on it, increasing it.