How Does a Reference Rate Differ from the Last Trade Price on a Futures Exchange?

The reference rate is an independently calculated price (often an average over time and across exchanges) used for final settlement at expiration. The last trade price on the futures exchange is the price of the most recent transaction on that specific exchange, used for daily mark-to-market and trading decisions.

The reference rate is designed to be a final, unmanipulable benchmark, whereas the last trade price is a dynamic, real-time value.