The index is calculated on a total return basis and is intended to reflect (1) the performance of a rolling position in specified gold futures contracts that will become the first liquid nearby futures contracts three months in the future in accordance with a specified schedule and (2) the return that corresponds to the weekly announced interest rate for specified 3-month U.S. Treasury bills. The ETNs are medium-term notes that are senior unsecured debt obligations of Barclays Bank PLC.