Gold prices rose 0.12 per cent toRs 31,779 per 10 grams in futures trade Wednesday as speculators built up fresh positions, shrugging-off weak overseas trend.At the Multi Commodity Exchange, gold for delivery in February traded higher by Rs 38, or 0.12 per cent, at Rs 31,779 per 10 grams, in a business turnover of 2,085 lots.Analysts said the rise in gold prices at futures trade was mostly on the back of fresh positions built up by participants but a weak trend overseas, limited the gains.Globally, gold fell 0.20 per cent at USD 1,282.97 an ounce in Singapore.