Selling everything can be good, but it also depends on the point if you think you will make more profit in the future, I would not do it.
I even think because of the halving the bitcoin will go to a much higher amount, after the halving has been done they people will sell of course and than its the point to sell them on the best moment to make a lot of profit.
Selling everything would only be a good thing if the investment was completely compromised. Most of the time, there are chances that the investment can recover its value. I think the percentage of assets to be sold should depend on the chances that this investment has to recover.