A method for setting margin requirements that evaluates positions as a group or portfolio and takes into account the potential for losses on some positions to be offset by gains on others. Specifically, the margin requirement for a portfolio is typically set equal to an estimate of the largest possible decline in the net value of the portfolio that could occur under assumed changes in market conditions. Sometimes referred to as Risked-Based Margining. Also see Strategy-Based Margining.
Source: Commodity Futures Trading Commission