In my opinion, in investing what is needed is patience and also making the right strategy when we have to sell or when we have to buy. If we have decided to invest long-term, I don't think we need to think about the daily price movements because it can interfere with our psychological
Thats the advantage of holding for long period, you dont need to worry for the current price and the roller coaster movement of the market since you already set a time frame on when to hold your coins.
On the other side if I want to buy bitcoin I wont sell my altcoins to be able to buy. I will use fiat instead because it would be best to diversify and never stick in just one coin no matter how profitable it is.