i think you have the point to decide when the right time to pull out your investment because its all about how much you want to take profit in crypto. my suggestion is don't be greedy when you can take the highest profit because the price will be drop suddenly and you only can take small profit. its happen to me in the past so i think its better if you have a set price on how much you wan to sell and take that profit.
Yes, sometimes greed can be bad. Rather than expecting price to rise better take out initial investment and sell only those coins. Rest all can keep for rolling. As fluctuation can totally shatter the market.
My favorite quote about investing -- yes, even better than "Buy low, sell high" -- is "Pigs get fat. Hogs get slaughtered." In other words, it pays to be greedy, but not too greedy. None of us can predict the future, but with a little self-discipline, we can take advantage of trends and make a good return on our investment.