Spot rubber made further gains on enquiries from tyre sector as sellers stayed back tracking the sharp gains in the global markers. RSS 4 improved to ₹138 (136) a kg, according to traders. The grade finished firm at ₹138 (134) and ₹135(131) respectively, according to Rubber Board and dealers. December futures weakened ₹136.00 (137.70), January to ₹141.35 (143.26), February to ₹144.98 (146.02) on the National Multi Commodity Exchange. RSS 3 (spot) flared up to ₹160.68 (155.14) a kg at Bangkok. December futures slid to ¥280 (₹160.59) on the Tokyo Commodity Exchange.