Complex sentence: One of them was a dominance in high yield fixed income securities in both underwriting and trading by picking up most of the expertise from Drexel Burnham Lambert after its demise in the late 1980s.
Split into simpler sentences: One of them was a dominance in high yield fixed income securities. They gained this dominance in both underwriting and trading by picking up most of the expertise from Drexel Burnham Lambert after its demise in the late 1980s.