New York-based MF Global, which specialized in trading futures and options, was headed by former New Jersey Governor and U.S. Senator Jon Corzine. It collapsed in Oct. 2011 after making a disastrous bet on European debt.
Regulators have been investigating whether MF Global tapped money from clients' accounts as its financial condition worsened. That would violate securities laws because brokerages are required to keep customer money separate from the firm's money.
Much of the money that went missing belonged to farmers, ranchers and other business owners who used MF Global to reduce their risks from fluctuating prices of commodities like corn and wheat.