Lets take the following example. You buy BTC at 6k and it goes up to 8K. Do you sell 100% of it or do you sell 75% and keep 25% in BTC.
What are your opinions / tactics?
Selling everything or part in my opinion depends on the situation or condition of each person. If at that time the person is in need of money, selling everything is the right choice. But, if the person is in a good condition then selling and storing a portion is the right thing to do. So, what tactics or strategies will be taken depends on the conditions of each person.