Bitcoin investments is a very promising investment which although seems to be of long term returns.most persons are not patient enough to wait till the value of Bitcoins rise significantly .
Soo in general how much should one invest in Bitcoin should it be "how much you can easily invest without stress " or "as much as you can invest at all cost"
Although I am aware it isn't a do or die affair
I would say as much as one is comfortable losing, investing in bitcoin is indeed a good investment, but still, we can not rule out the risks involved, the same as it is with every assets out there requiring investment.
For me, If I have the money, I can invest a million dollar, 2 million dollar, 5 or even 100 million dollar, as long as I have the money and I can comfortably do away with it for a very long time..
Bitcoin investment is much more profitable when done and left for the long term, than it is for the short term.