Complex sentence: The entity issued 19 tranches of mortgage-backed bonds worth $947 million--four senior ranches rated triple A. Eleven "mezzanine" tranches--three rated AA, three A, three BBB and two BB (junk).
Split into simpler sentences: The entity issued 19 tranches of mortgage-backed bonds worth $947 million. Eleven tranches were "mezzanine"--three rated AA, three A, three BBB and two BB (junk).