5 Dollars - Elizabeth II 4th Portrait - Koala - Platinum

The Perth Mint's platinum koala series, running from 1987, was among the first platinum bullion programs issued outside of the Soviet Palladium and South African Platinum markets to gain serious collector traction. The 1/20 oz denomination was added specifically to create an accessible entry point for platinum stacking at a time when platinum was trading above gold. By 2001, that premium had narrowed considerably, which suppressed demand for fractional issues and kept mintages on the smaller platinum fractions relatively tight.