maybe, or maybe there is a bank that supports and is ready to print money on every bitcoin exchange to fiat? I also haven't found a theory about it.
Yeah bitcoin has real money on its back because when I buy bitcoin I will have to pay for it. Exchange will convert my local currency into dollar and then into bitcoin. Thats why I can say that all the bitcoin in the world has a value in real money and you can cash your coins any time for real money. Ups and downs do not affect the capitalization of real money.