Spot rubber closed unchanged on Thursday. RSS 4 was quoted steady at Rs 137.50 per kg by traders and the Rubber Board. It finished flat at Rs 133.50 per kg according to dealers. The commodity lost its direction as there were no quantity buyers or sellers in the local trading houses. But it managed to sustain at the prevailing levels mainly on supply concerns. The overall volumes were low. In futures, the February contracts improved to Rs 141.34/kg (Rs 140.89) and March to Rs 144.01/kg (Rs 143.38) for RSS 4, while April contracts dropped to Rs 147.25/kg (Rs 147.52)on the Indian Commodity Exchange (ICEX). The near month February contracts were up 0.35 per cent with a volume of 287 lots and total traded value of Rs 405.49 lakh.