Benchmark Tokyo rubber futures surged to a 3-month high on Friday as risk appetite grew on the back of a recovery in commodity prices and strong price momentum, helping it mark its biggest weekly gain since May 2013. The Tokyo Commodity Exchange (TOCOM) futures, which set the tone for tyre rubber prices in Southeast Asia, rose for a fourth straight session, aided by tighter supply due to the wintering season in Southeast Asia and export cuts by top Asian producers. "On top of the recent recovery in commodity prices and equities, lower supply from Southeast Asia helped improve investor sentiment," said Jiong Gu, analyst at Yutaka Shoji Co.