This week, Fitch Ratings downgraded Washington Mutuals covered bonds to AA- from AA and placed them on rating watch negative, after last weeks downgrade of the issuer default rating of the program sponsor, JPMorgan Chase Bank. That rating action followed JPMorgan Chases disclosure last week of a $2 billion trading loss on its synthetic credit positions in its chief investment office. The positions were intended to hedge JPM's overall credit exposure, particularly during periods of credit stress. That loss estimate has since grown to $3 billion, it was reported this week. The JPMorgan...