Mustard seed recorded a rise of Rs 11 at Rs 3,986 per quintal in futures tradeamid building up fresh positions by the participants in line with a firming trend at the physical markets. At the National Commodity and Derivatives Exchange, mustard seed for the most-traded delivery in June went up by Rs 11 or 0.28 per cent to Rs 3,986 per quintal, persisting an open interest of 1,08,080 lots. In a similar way, the delivery of the July looked up by Rs 11 or 0.27 per cent to Rs 4,027 per quintal, having an open interest of 48,770 lots. Building of fresh positions by speculators on the back of a firm trend at the spot markets on increased demand and restricted arrivals from growing regions and increased offtake by oil mills, mainly supported the upside in mustard seed prices at futures market here.