what range would you say is reasonable for this purpose. e.g. from case 1: -10% anual return to 5: 50% anual return (just as example, not what I am using now).
What range would you use and why?
I don't think there is limit to how we can earn from our investment in Bitcoin, once we have the tenacity to invest and hold for some time till it becomes more profitable for us to sell, in my own case, any percentage is fine and ok by me, as long as am going to break even from it, once am not at loss, anything should be a profit except if am being greedy or something else.
Exactly, we can't predict the market and by the history of bitcoin we can't get huge profit easily we need to invest for the long term before you can be successful on it. Because many people that have be in wealth in bitcoin invest for long term. If we says we will be setting a range you will be greedy because you will always want to have huge profit before selling your coin. we can't predict bitcoin because of is volatile. If someone invest in bitcoin now In the next 10 years am very sure that you will be in profit, even is not double of is investment but you will surely get something at of it. that is why investing in long term is the best and will always minimize your risk from losing a lot in the market.
In my opinion, Anyone that have the capacity to invest in bitcoin will do so and he will always wait for profit before he sells. I don't think I usually focus on range because even we predict it he can probably change. So I just double my investment anytime I have the funds. and if I have small profits I usually sell it out. I don't want to be greedy because If you are someone that get profit and still leave it. waiting for huge profit always failed sometime because the market is not always friendly and you can lose your capital for some time because of the volatile.