A sightholder is a company on the Diamond Trading Company's (DTC) list of authorized bulk purchasers of rough diamonds. DTC is controlled by the De Beers Group, the single largest producer and purveyor of rough diamonds in the world. In May 2006, DTC released a list of the 93 sightholders on its website.
The DTC Sightholder list was further reduced to 79 companies worldwide in December 2007. The list of selected companies for the 2008-2011 contract period was published in April 2008.