That makes no sense your question, why ask when to sell? For sure everyone will say that the best time to sell is when your investment coins increases, makes a profit and can also return more than your initial capital. in investing you need to determine profit targets. and vice versa the question is what coins do you hold at the moment?
you don't have to aim for a big profit because that's one of the reasons why sometimes an investor regrets why he didn't sell it immediately when his capital became x2 you're right it's better if it has a target price and don't be greedy at the price he wants for sale his altcoins because many whales when it comes to investing or trading when they know the price will fall.