Traders will be watching to make sure a combined entity doesn't use its influence to drive up fees, said Joseph Cangemi, chairman of the SecurityTradersAssociation.
"I view Mark as a friend, and I find today's news totally shocking, out of character and horrible, " said John Giesea, chief executive of the SecurityTradersAssociation, where Mark Madoff once served as a governor and president of the trade group's New York affiliate.