Thai rubber futures ended lower on stop loss sales on Monday as overall volume rose to 90 RSS3 contracts, up from 37 last Friday, brokers said.
The most active December contract ended at 52.8 baht per kg with 38 contracts traded, down from 53.2 baht with seven contracts traded last Friday.
"Speculators were making stop-loss sales in the medium and distant contracts on expectations of the price falling further, in line with the spot market," said one broker.
The price of ribbed smoked sheet number 3, RSS3, in Thailand's Hat Yai physical market has been declining over the past week due to rising supplies, brokers said.
RSS3 was at 50.96 baht/kg on Monday, down from Friday's 51.68 baht.
Thailand's south, which produces about 90 percent of the country's natural rubber, usually sees its peak period of production from June to September.