MF actually was more expensive in commisions than other firms. You could get cheap trading only through its introducing brokers.
Huh? MF was more expensive than the other large FCMs? Before you answer, look closely at lists of the largest firms, such as this one from a couple years ago: 01 GOLDMAN SACHS & CO 02 NEWEDGE USA LLC. 03 JP MORGAN FUTURES INC 04 UBS SECURITIES LLC 05 CITIGROUP GLOBAL MARKETS INC 06 MERRILL LYNCH PIERCE FENNER & SMITH 07 MF GLOBAL INC. 08 DEUTSCHE BANK SECURITIES INC 09 BARCLAYS CAPITAL INC 10 MORGAN STANLEY & CO INCORPORATED