Spot rubber flared up on Monday as tyre companies bought the raw material up to ₹128 a kg from the local trading houses. Sentiments continued to remain bullish tracking the overall gains in domestic futures and global trendsetters. RSS 4 improved to ₹130 (128) a kg as quoted by the traders. The grade firmed up to ₹128 (125) and ₹125 (122) respectively, according to Rubber Board and the dealers. April futures flared up to ₹136.97 (131.71), May to ₹137.69 (132.40) and June to ₹137.69 (132.40) a kg on the National Multi Commodity Exchange. RSS 3 (spot) closed at ₹113.70 (110.19) a kg at Bangkok. April futures firmed up to ¥186.5 (₹114.42) on the Tokyo Commodity Exchange. Spot rubber rates (₹/kg): RSS-4: 130 (128); RSS-5: 128 (125); Ungraded: 125 (119); ISNR 20: 121 (119) and Latex (60% drc): 98.50 (96).