 The WCU was first intended to be the basis for denominating global bonds, a debt instrument that is issued globally and is subscribable by people and institutions around the world.Simply put, it is a GDP-weighted basket of key currencies each of which is indexed against inflation for the relevant countries.The WCU is defined with respect to a base year, so that each unit represents the same global purchasing power as at that base year, when it is equal to US$1.