How do passive fund managers use swaps to replicate an index?

Passive fund managers can use synthetic replication to track an index through derivatives like swaps. In this arrangement, the fund agrees to pay a pre-defined return (e.g., LIBOR or a fixed rate) to a counterparty in exchange for the counterparty delivering the total return of the index. This approach allows the fund to replicate index performance without holding the physical securities, reducing costs and eliminating tracking error.