Cost of sales increased to US$3.8m from US$3.2m in 2020 primarily reflecting the increased volumes and increases in the price of the vanadium concentrate purchased at the high prices prevailing in 2019 and utilised in 2020. The largest part of cost of sales is the purchase of raw materials, the price for which is determined as a percentage of the value of the content of vanadium at prices prevailing at the time of purchase. Since such materials are purchased up to several months before processing, and sales price determination is made several months after shipment, the prices used as a basis for the calculation of raw material prices were significantly higher than the price used as a basis for product sales. This means that the operating margin was squeezed as prices were kept low in 2020. Again, during times of rising prices this effect would be reversed and is likely to even out in the long term as prices move up and down.