It is no secret that today, almost all modern banks operate on the basis of fractional reserves. To put in simpler terms: banks only has in their vaults a small percentage of the money that their customers gave them; if a large enough number of customers of a specific bank want to get their money back, the bank wouldn’t be able to meet the demand. Before there was modern central bank system, the bank could either have to borrow or file for bankruptcy. The central banks by design had infinite ability to lend, for they can legally conjure up money from thin air – there is a reason that modern currencies are called fiat money.
The Bitcoin world doesn’t have central banks, and this fact even appeal to some of its supporters with libertarian inclinations. Among these people, a widely-held belief is that bailing out insolvent banks is no different from highway robbing; if a bank screws up, the argument maintains, it should face the consequences alone, rather than letting all economy participants across the system to share the pain in the form of debased per unit currency value.