A better question in my opinion should be "why are you selling bitcoins?". When it comes to saving money I don't really have a goal in mind, I mostly save money for bad times like important renovations in the apartment or when the car breaks down. For me bitcoins is a means to save money each month and I prefer to do in bitcoins and not in fiat money. I already have my monthly salary coming in fiat money, the same goes for my retirement money that will be paid out eventually in fiat money. Having the chance to save money in bitcoin is a good diversification that will payoff long term. Also with inflation rates of 10% in fiat money and banks paying 1-2% interest it makes absolutely no sense to save money in a bank account. Taking profit is not really a plan for me, because that would mean to go back into fiat money - which I am trying to escape.