There are a lot of ways though:

a. sell all your altcoins, 100%
b. sell at least 50% of it when the price hits all time high and wait. Then sell the next 50% if it goes up again. If not they wait a little bit or maybe you will continue to accumulate once more.
b. I see others sell at 80% of their assets and take profits and then leave 20% for the next accumulation phase for them.

So it's really up to you on how you strategized or how to look at the long term prospect, one cycle or more hold?