Spot rubber improved on supply concerns, though there were no quantity buyers in the market. RSS 4 firmed up to ₹121 (₹120) a kg, according to traders and the Rubber Board. The grade closed marginally higher at ₹118 (₹117) as reported by the dealers. October futures improved to ₹121.50 (₹119.38), November to ₹121.50 (₹119.49), December to ₹122.35 (₹120.19) and January to ₹122.99 (121.26) on the National Multi Commodity Exchange. RSS 3 (spot) firmed up to ₹110.73 (₹110.06) per kg at Bangkok. Spot rubber rates (₹/kg): RSS-4: 121(120); RSS-5: 114(113); Ungraded: 100 (99); ISNR 20: 96(95) and Latex (60% drc): 76 (75).