Buy and sell is not a sure thing. do the action buy and sell bitcoin in my opinion must be in accordance with the condition of bitcoin market conditions. because the ever-changing graph of the movement demands that we always play an active role in making the best decisions. if talking about today then I prefer to sell, I see hardfork will slightly disturb the bitcoin price. so it could be after hardfork bitcoin prices will decrease and this is a thing to be avoided. selling current at the $ 5500 price fare could be an option and maybe we can buy another bitcoin when the price drops below 5000 $.