The safest time to invest in bitcoin is when no one is talking about it.  If you invest now, you might 2x your money in a month, or you might be underwater for 4 years.  

Average long term returns over any 5 year period are fantastic (value goes roughly 2.5x per year), but if you can't guarantee that you can leave your money in for that long, it's very risky.

I made a figure to illustrate:

Originally published on Facebook