However that doesn't mean bitcoins are in a bubble, for that the true value would have to be lower than what it is. And I don't know how to even roughly estimate bitcoin's true value. That is, what the price will turn out to be in the long run, what the supply and demand will be. That depends on how big the bitcoin economy will grow, and the hype, while irrational, might actually bring enough people to it to make it work. Or it might just die as people get disappointed or move onto the next thing.