1. A system for enforcing rules-based portfolio compliance, said system comprising: a compliance rules computer coupled with an electronic data network and configured to maintain computer accessible data for a plurality of portfolio compliance rules; and a compliance-engine computer server coupled with said electronic data network and configured to execute a compliance analytics engine (CAE) operative to receive from an order management system (OMS) via said electronic data network, an electronic request to evaluate compliance of a set of proposed electronic trade orders stored on said OMS prior to execution of said trade orders, to access said plurality of portfolio compliance rules maintained on said compliance rules computer server, to perform a compliance evaluation of said set of proposed electronic orders based at least in part on the portfolio compliance rules, and to generate an electronic message including data for one or more violations of the portfolio compliance rules to the OMS based upon said evaluation.