To answer these questions for the US futures market: The options clearing corporation [OCC] is the organization that performs clearing and alleviates most of t

To answer these questions for the US futures market: The options clearing corporation [OCC] is the organization that performs clearing and alleviates most of the counterparty risk. They demand deposits from various member companies to ensure that, if a member defaults, at least the other parties get their payments. Organizations such as SIPC offer protection for investors in the case that brokerage firms belly up. They are government-backed. It's hard for a private company to do that. Leverage involves a contractual agrement which generally involves some sort of clause that allows the broker to go after your company assets, and sometimes even your personal assets, if you blow up. And the brokers generally have enough cash to provide necessary float (in case of a failure to meet requirements). zhoutong, it's useful to study how existing futures markets work, and try to see how you can replicate some of those key facets (like counterparty risk)