Spot rubber made further gains as certain tyre companies joined the buyers queue on Monday. RSS 4 improved to ₹144 (₹143) a kg, according to traders. The grade firmed up to ₹143.50 (₹ 143) and ₹140.50 (₹140) respectively, according to the Rubber Board and dealers. August futures closed at ₹141 (₹140.56), September at ₹136.25 (₹135.73) and October at ₹132.85 (₹132.93) on the National Multi Commodity Exchange. July futures weakened to ¥188.3 (₹119.31) on the Tokyo Commodity Exchange. Spot rubber rates (₹/kg): RSS-4: 144 (143); RSS-5: 141 (140); Ungraded: 116 (115); ISNR 20: 121 (120) and Latex (60% drc): 90 (90).