I think the real question here is, is any money you put anywhere "safe"? The USD is only valuable because of the faith that everyone puts in it. The same with stocks, bonds, gold, and soybeans. Tomorrow everyone could decide that all all-soy diet will change their life and make them lose weight and soybeans could end up becoming very valuable because people believe other people will buy those soybeans in the future. You have to remember the bitcoin is deflationary and a fixed supply and dollars are not fixed. It is also possible to hedge your bitcoin bets with futures contracts or by shorting at the right times, setting stop-losses, etc.