I'd like to make this observation; say, today, the bonds of Deutsche Bank rally strongly and the stock is up something like 12%. Deutsche Bank announced that they will buy back some bonds.
Now when you think it through, with whose money? They have a capital shortage, that's why the stock has collapsed by more than 80% since the financial crisis in 2007.
The reason they can buy back bonds is that someone is lending the money. But why would anyone lend them the money to buy bonds that essentially that have collapsed this year by something like 20, 30%? Who is lending them the money? The central bank of Europe, the ECB, or the Federal Reserve, or someone innocent. What will eventually happen is a crisis that brings down central banks. But I don't know when, but it's going to happen.