If your whole portfolio is only altcoins, then there is no point in holding it for a long time. If you see you recovered your loss already, sell a portion of your holdings every two weeks. If you had Bitcoin, the suggestion could have been something else. Everyone has a target I guess. I have a target that I won't sell until Bitcoin touches the 80K mark. You might have your own target.
If you reach your desired price, do not wait for a further pump. People usually hold longer expecting it will grow more and more. But the process is no infnite, it will start collapsing at some point.
I will not give him such a suggestion to sell after every two weeks, even if we are talking about Alts or talking about BTC. And his portfolio is still down 17%, which means, he is not in the position to book some of the funds, instead, he should wait further because the overall market will come down again to retest its supports and at that time OP will think he should have booked his investment even at 17% down.
But, look at the bigger picture, which is to hold those funds for a longer period of time, if OP will abled to do that, he might be making 3x or 10x on his investment, because BTC has the potential to give the maximum of 3x and minimum of 2x but in alts, we can make 10x if we have chosen the right one.
Now all the game revolves around the alt token that OP has selected for holding purposes, and the best way for OP to avoid getting thoughts of booking profit is to move funds from exchange to some non-custodial wallet, where you cannot trade them quickly. For example, if you will move funds to the Trust wallet, then to make trades you will have to send funds again in Exchange which will cost you some fee and you might not want that.