However I have another theory. The Bitcoin market is not regulated by FSA or any other authority. It is incredibly easy to make manipulating transactions on this market. Given that the value of all outstanding Bitcoins is worth something between less than $1billion and $3billion (depending on the current rate) such transactions can be made by the investments of just some hundred million dollars. I am sure that with such a small and non-regulated market the Bitcoin rate is just a toy for a small group of speculators. A very profitable toy.