Worldwide, especially in my place, must sell it for profit rather than always keep it!
The government always forbids the use and play bitcoin so that it can not grow fully potential in my place. Surely it remains an advantage if there is a transaction rotation for bitcoin in my country to live.
People sell their bitcoins because most of the time they need it in emergency case. Another reason is because they need fiat than digital currency which is only limited for transactions compared to fiat which is worldwide. And common reasons are doubt about bitcoin's future, doesn't have enough knowledge about crypto coins and the strategy of "buy low, sell high. There are many reasons.