You can hold Bitcoin has long at you want depending on the nature of the market. There are people that had been holding Bitcoin for a long time and they are still holding till now. All this depends on why you are holding especially for people that are self sufficient. People that have enough funds to buy more Bitcoin to their portfolio when they see that the price of Bitcoin is going down. More people tend to buy more Bitcoin when they see the price going down.  When the price goes up, they may decided to sell their Bitcoin holdings.