A system and method of trading commodities includes an open commodities exchange server which can be accessed by registered customers. Registration of the customers with the system includes providing information to the system which identifies the customers and the deposition by customers of commodities with one or more custodians. Orders associated with commodities are posted by the server as offers on a data base after they have been securitized. Registered customers can then review the offers and generate responses thereto. These responses are also securitized to insure that the proper securities or assets are on deposit with the custodian. The custodians having their own servers.