Abstract: In this paper we will present and discuss four different methodologies for calculating ERISA damages — what we will label the “best-performing fund,” “portfolio redistribution,” “most similar fund,” and “10b-5 style” ERISA damage methods. For purposes of demonstrating how these ERISA damage methods work in practice we will use facts and data from an actual ERISA litigation matter. These different ERISA methods can result in strikingly different damage estimates. In the ERISA matter we analyze, for instance, aggregate damages can range from less than U.S.$3 million, using the “most similar fund” approach, to well over U.S.$2 billion using the “best-performing fund” ERISA damage method.