1. A system for trading, comprising: a computer having a processor and a memory, the processor configured to: receive an indication to automatically group a set of individual investment instruments held by a user, each of the set of individual investment instrument having a quantity of units associated therewith; determine a set of possible strategies, each possible strategy comprising one or more units of the quantity of units of one or more of the set of individual investment instruments held by the user; determine a set of groupings of strategies from the set of possible strategies, each grouping comprising a non-overlapping combination of strategies of the set of possible strategies which together include all units of the quantities of units of all of the set of individual investment instruments held by the user; and determine one or more selected groupings from the set of groupings of strategies based at least in part on a selection criteria; and a memory coupled to the processor and configured to provide the processor instructions.