When the world’s most important diamond buyers arrived at De Beers’ offices in Botswana late last month, they were presented with a rare offer by their host: the option to buy nothing at all.

De Beers markets its rough diamonds in a series of tightly scripted sales, where handpicked buyers are normally expected to take all their contracted allocations at a price set by De Beers, or face potential penalties in the future. But with prices in free fall around the world, the one-time diamond monopoly has been forced to allow more and more flexibility, finally removing the restrictions altogether.

Bloomberg