Hodling is good only for those who have been holding their coins since early times, and are still holding for more. Those who bought at high are holding it due to the fact that they don't want to lose on their investment (retail investors) and other big investors also don't want to lose that huge percentage of their earnings at low price. Trading is best for those who understand the market and can time their trades carefully so that even if they lose, their loss isn't so big for them and they can continue playing with the market, trade more and earn more.