State-issued coin series are popular worldwide - not only because of their artistic designs and thematic variety, but also due to their potential for value appreciation. Particularly noteworthy are series such as the South African Big Five, the Australian Kangaroo, Koala, Kookaburra, as well as the Chinese zodiac–inspired Lunar Series.

These series are issued by national mints such as the South African Mint, the Perth Mint (Australia), or the Royal Mint (United Kingdom), produced in high minting quality and typically made from precious metals like gold, silver, or platinum. They are often so-called “bullion coins,” investment coins that can develop collector value in addition to their intrinsic metal value.

The Big Five series from South Africa features impressively detailed depictions of the “Big Five” of the African wildlife - elephant, lion, leopard, rhinoceros, and buffalo. These coins are issued in limited mintages and are highly sought after by collectors and investors worldwide. First issues and complete sets, in particular, often achieve high prices on the secondary market.

The same applies to the Australian Lunar Series, which features a different animal of the Chinese zodiac each year. The Perth Mint releases this series in various sizes and metals—usually highly limited and with special attention to minting quality. Certain years or rare denominations have already seen significant increases in value.

The Australian Kangaroo, the Koala, and the Kookaburra are also among the internationally recognized classics of coin series. They are issued annually with changing designs and often in limited quantities. This combination of artistic appeal, government backing, precious metal content, and limited mintage makes them highly attractive investment and collector items.