[iforgetti]

They may be collateralized by bonds worth even less than that.

If the bonds were worth 80 cents on the dollar than they just traded 80 cents on the dollar for 99.9 cents on the dollar. A good deal if your balance sheet is in such poor shape.

[HDThoreaun]

Unless the bank fails that doesn't matter. And the banks won't fail because the incentive to run them is gone now. Everyone will see their deposits are safe and the banks can give the money back with interest.