Mortgage Holding Co. Stock Down 50% For Week

The shares of Doral Financial have lost almost half their value the past 3 days, including an 18.5% drop today. Standard & Poor's downgraded the firm after affirming its rating only last week. The market cap now stands at $2.32 billion.

Recent financial reports seem to show the Puerto Rico based corporation operating normally. But rumors of a $200 million "trading activity" loss is the likely source of the selling. Such losses could spring from derivative strategies these holding companies use.