Spot rubber prices strengthened further on Monday due to increased demand from tyre makers, the largest consumers of the commodity. The daily reference price for RSS 4 was quoted higher at ₹134.60 (132.45) a kg by the Rubber Board. February futures weakened to ₹124.81 (125.25), March to ₹126.15 (126.91) on the NMCE. RSS 3 (spot) firmed up to ₹112.15 (110.36) a kg at Bangkok. February futures slid to ¥ 212.8 (₹111.56) on the Tokyo Commodity Exchange. Spot rubber rates (₹/kg): RSS-4: 133.50 (131); RSS-5: 113 (107); Ungraded: 106 (103); ISNR 20: 107 (105) and Latex 60%: 81 (81).