Smart trading means you don't lose and you earn even if the currency you entered stays at the same purchase price.
So, if there's a currency at $100 and you have $100, don't invest all of it because if the currency crashes, you'll lose your money. Even if you leave it hoping it returns to at least the purchase price and it actually does, you wasted all that time without making a profit.
Start by investing $20; if the price drops, buy again with $20; if it drops again, buy another $20. If the currency rises to the original purchase price of $100, then you will have made a profit from the trades you entered when the price dropped.