Selling is always depend on the movement or maybe the volume of the coin. I beleive that selling in a low price is a loss, so selling is always on a high price, but i believe that it is also depend on the volume of the coin because we dont even know about the coin status if it will fall or rise up high so i think we also need to see the volume.
Aside the volume for me, I also consider the project itself, if it’s a project I am not so sure of its future and the value too is gradually depreciating, I sell then off quickly even when I have made little loss to buy bitcoin, because I know that no matter how, now that we are just at the beginning of Bull, Bitcoin will definitely give me such loss back, so there was no point holding such coin.
But for BTC, I am in to for a long term and not a short term, I don’t do short term trading, so it will be much more easier for me to decide when to sell off which will be based on the percentage increase of my coin, anything that can give me 200% increase on my investment, is quite ok for me, fare better than just keeping the fund in my traditional bank without any profit on it.