You already got the favor of taking those profits while you can because it cannot escape afterwards the possible dumping of it.
I don't know if you can call it greedy as well because he must have thought HEX could become just like the new Bitcoin that will keep going up. This is why it's true that we need to take profit but one would rather learn when to trade and take profit when there is a chance.
But if he prefers to keep holding, he better just sell and buy back at the right time. Because just like Bitcoin HEX or any other altcoin, the bull runs cycles too.