Spot rubber prices were firm on Thursday. The market opened steady but regained strength during late trading hours tracking the sustained gains in global trendsetters. RSS 4 improved to ₹140 (₹139) a kg, according to traders. The grade finished flat at ₹139 and ₹136 respectively, according to the Rubber Board and dealers. January futures slid to ₹138.30 (₹139.82), February to ₹143.40 (₹143.88), March to ₹146.88 (₹147.30)on the National Multi Commodity Exchange. RSS 3 (spot) improved to ₹157.85 (₹155.29) at Bangkok. January futures firmed up to ¥ 272.1 (₹158.60) on the Tokyo Commodity Exchange. Spot rubber rates (₹/kg): RSS-4: 140 (139); RSS-5: 130 (130); Ungraded: 118 (117); ISNR 20: 128 (126) and Latex (60% drc): 84 (83.50).