Spot rubber firmed up further as the market resumed upward journey reacting closely to the global gains and domestic supply concerns. RSS 4 improved to ₹140 (₹138) a kg, according to traders and the Rubber Board. The grade was quoted firm at ₹137 (₹135) by dealers. July futures flared up to ₹ 146.24 (₹141.59), August to ₹142.50 (₹137.69) and September to ₹138.20 (₹134.31) on the National Multi Commodity Exchange. RSS 3 (spot) improved to ₹117.31 (₹115.36) at Bangkok. July futures firmed up to ¥162.5 (₹107.89) on the Tokyo Commodity Exchange. Spot rubber rates (₹/kg): RSS-4: 140 (138); RSS-5: 136 (135); Ungraded: 120 (117); ISNR 20: 119 (118) and Latex (60% drc): 100 (100).