Spot rubber finished firm catalysed by the sharp gains in domestic futures on Wednesday. RSS 4 improved further to ₹136 (₹135) a kg, according to traders. The grade firmed up to ₹134 (₹133) and ₹131 (₹130) respectively, according to the Rubber Board and dealers. The trend continued to be mixed. July futures flared up to ₹138.99 (₹133.73), August to ₹135.51 (₹131.46) and September to ₹133.69 (₹129.80) on the National Multi Commodity Exchange. RSS 3 (spot) increased to ₹107.44 (₹105.40) at Bangkok. June futures weakened to ¥159 (₹102.53) on the Tokyo Commodity Exchange. Spot rubber rates (₹/ kg) follow: RSS-4: 136 (135); RSS-5: 132 (131); Ungraded: 114 (113); ISNR 20: 115.50 (115) and Latex (60% drc): 100 (100).