Arnoldo Efron (2019)

Arnoldo Efron is a pioneering figure in numismatics who has dedicated over sixty years to the study and documentation of world currencies and banknotes. A native of Argentina, Efron is the founder and head of the Houston, Texas-based Monetary Research Institute and a Life Member of the International Bank Note Society.

Efron's most significant contribution to the field is the MRI Banker's Guide to Foreign Currency, widely regarded as the "Bible of Foreign Currency." Since its inception in 1990, over 90 editions have been published and distributed worldwide. Banks, currency exchanges, hotels, and collectors on every continent rely on this invaluable reference to verify currencies and determine legal tender status. Efron continues to update the publication through tireless daily research.

Since 1975, Efron has established himself as the preeminent authority on foreign currencies and banknotes. His expertise in Uruguayan banknotes led to the publication of a specialized book on the subject. His encyclopedic knowledge and willingness to assist collectors, dealers, researchers, and businesses have made him instrumental in preventing costly errors and advancing the hobby globally.

Beyond his publications, Efron is renowned for his character and integrity. He has generously shared his knowledge with newcomers and established collectors alike, helping many enter the field. Colleagues praise his honest dealings, exceptional customer service, and genuine humility. His editorial assistance has been invaluable to major cataloging projects, and his availability to answer questions — no matter how detailed — has become legendary. His contributions have fundamentally shaped modern banknote collecting and made it an infinitely more pleasant and informed pursuit for enthusiasts worldwide.