You have a point about the 2 year chart.  However, I believe the 2 year downward trend was caused by long term investors getting fatigued from the tremendously long process of getting Gahcho Kue off the ground and permitted.  Now De Beers is taking the lead of the major diamond producers, but will have healthy (but good for the industry) competition from Dominion Diamond.  Unfortunately, Dominion will have to get the Ekati situation resolved first.