It's only loss if you sell.
If you bought Bitcoin at 120€ and sold it at 80€ two days later, you made a loss.
If you sold them 2 month ago...
If you think something you "invest" in is going to a total loss - then don't start putting money in in the first place.
Lenn - Sorry I don't think I was clear in my comment. I 100% agree with you, I just think these people that buy high and sell low are insane or not informed. I'm super confident and secure investing in most cryptos, especially Bitcoin.
Thanks for the laugh, @lennstar and @moondogcrypto!
As a beginning stockbroker, one of the the first things I learned was that paper losses are just that, and if you did your homework, and still have faith in the underlying security, they are meaningless.
As @lennstar said, it's only a loss if you sell, and since I'm actually following my own advice and only investing what I can afford to lose, I can hold indefinitely if I need to.