My option is short term investment. As  you can see, bitcoin is the most valuable thing in general and the price is unsteady so i chose short term investment because i can not know the time bitcoin will be collapsed. According to the information and number about bitcoin, i can see bitcoin will be more popular and influential in market and economy. However, bitcoin not my official job, i really interested in bitcoin but i just have used bitcoin to earning money and take that money to invest in something else; I still saving bitcoin for future but i will retire when i reach the goal which i have planned,  for example: 4 or 9 bitcoin will enough for me !