There is no guaranteed way to manage risks. Even in the stock market, which is considered more "civilized" than the crypto market, no one can predict anything. It remains only not to make rash decisions based on emotions.
You are right there is really no guarantee in fact there is no one who can ever say that you can sure have profit because it depends on us how much we are willingness we to take the risk. Some people are really aiming for the best but there is always consequence for it so we should need to be sure about how much we are willing to get change for the better and for the sake of our future.