A friend of mine just called Bitcoin "monopoly money".
After a comeback from me, he admitted that the comparison isn't really fair, and a better comparison is junk bonds
I think that's a somewhat decent comparison. Obviously they're not really the same thing, and are very different technically and capabilities wise, but putting technical differences aside, both are investment instruments that are traded at relatively "low valuations", with high risk of "defaulting" and in contrast high yields.
Of course with Bitcoin nobody can "default" on you, because a Bitcoin is not an obligation to pay, but it can crash to zero tomorrow.
Maybe we should pitch Bitcoin as an alternative investment for junk bond traders?