Complex sentence: Whereas today, the Federal Reserve's margin requirement (under Regulation T) limits debt to 50 percent, during the 1920s leverage rates of up to 90 percent debt were not uncommon.
Split into simpler sentences: Whereas today, the Federal Reserve's margin requirement (under Regulation T) limits debt to 50 percent. During the 1920s leverage rates of up to 90 percent debt were not uncommon.