(Bloomberg) -- Credit Suisse Group AG peddled a series of unusual bonds in recent years that gave the Swiss firm insurance against the equivalent of a banking earthquake. The owners of those securities are feeling some tremors.The $461 million of notes, which are rarely traded, were quoted at distressed levels last month, with a sliver of the issue selling at around 60 cents on the dollar. Traders at JPMorgan Chase & Co. recently offered to buy the junior tranche of the notes for around the same.