First published by Money Metals here: https://www.moneymetals.com/news/2017/01/12/silver-mining-profit-margins-000986

The profit margin trend at the world’s largest primary silver mining company has experienced a rapid decline over the past several years. Fresnillo PLC in Mexico, is the largest primary silver mining company in the world. For all their hard work, Fresnillo’s profit margin versus its cost of sales fell to an all-time low of 7% in 2015. This can most certainly be blamed on market intervention.