At the end of March, a rally was reported in the secondary rough diamond market. It was driven by expectations that De Beers will raise its prices and reduce its sales volume. That price hike occurred to the tune of about 3 percent and up to 8 percent in some cases, according to a Professional Jeweller article. ALROSA also reportedly hiked its prices by about 3.5 percent.
Polished prices have been firm over the past several weeks and trading volumes have been good. Some traders have reportedly been attempting to boost prices for some of the more scarce goods, but their efforts have been met with resistance.
Rapaport reported that "that diamonds between 0.30ct and 0.40ct, G to K colour, VS2 to SI2 were 'hot' in March, with prices for these smaller stones continuing to outpace other stone categories," the Professional Jeweller article notes. Further, "VS to SI goods through to two carats in size, with triple EX certified stones, are in strong demand and short supply."
However, Rapaport has warned that rough prices are not sustainable at the current level of polished prices.Diamond Market Update (April 11, 2013) from Diamond Investing News