I only buy bitcoin when i need it,and when i have money to buy some amount of it,and i wait for three to four months to sell it and make some.profit.
You only wait when you can guarantee that the price will increase in three to four months. For me, that is just a short term investment and usually that would not happen all the time that the price will increase in a given projections. If that trends happens all the time then we are all rich here already.