The rupiah traded at 9,165-9,170 to the dollar, compared to last Friday's close of 9,145-9,150.
"There wasn't much news today. At the most, people were waiting for the Fed announcement," said Panca Global Securities analyst Betrand Raynaldi, referring to an expected interest rate hike announcement from the US Federal Reserve on Wednesday.
Raynaldi said investor interest had not yet returned to market mover Telkom, and the stock had been trading flat to lower since the middle of this month.
He said sister company Indosat and cigarette firm Gudang Garam were also down, mostly on profit-taking.
Telkom was steady at 4,800 rupiah from an intra-day high of 4,825 and Indosat lost 100 rupiah to 5,700.
Gudang Garam was down 350 rupiah at 16,850, while rival Sampoerna rose 50 rupiah to 7,450. Car distributor Astra International was up 50 rupiah at 10,050.
Bank Central Asia fell 50 rupiah at 2,875 while state-owned Bank Mandiri was flat at 1,940. Bank Rakyat Indonesia was down 25 rupiah at 2,750.