Diamantino Leilões performes live and online numismatic auctions, and belongs to the main company Numismatica Diamantino, a very well-known brand in the Portuguese and worldwide numismatic business. The company exists since 1942 with a shop open to the public in Lisbon, and today it’s the oldest numismatic company operating in Portugal. The auctions business started in the 2000´s, and after a pause resumed in 2017 with the creation of the brand Diamantino Leilões. Since then, the auctions take place frequently.