The main index of Tehran Stock Exchange, TEDPIX, lost 40,586 points and fell 2.46% to retreat further toward 1,607,195 points.
The value of trade posted meaningful declines on Monday compared with the past two sessions, reaching 50 trillion rials ($217 million), according to Boursepress.ir.
This indicates a new low in the performance of market markers tasked since Saturday with boosting demand and helping liquidity of shares.
Persistent downturns have dashed the hope of large groups of retail investors about recovery anytime soon, drawing fresh concerns among the public, lawmakers and government officials.
Lawmakers have asked the CEO of the Securities and Exchange Organization, Hassan Qalibaf-Asl, to brief MPs about the current status of the market, Boursepress quoted Kazem Mousavai, a member of Majlis Economic Commsion, as saying.
Pointing to pattern of declines, the MP recommended retail investors to temporarily postpone any new investment in the market.
TSE Trade
About 5.32 billion shares valued at 46.157 trillion rials ($200 million) changed hands at TSE for the day.
Trading at TSE and over-the-counter Iran Fara Bourse starts on Saturday and ends Wednesday.
Iran Tire Company and Neyshabur Sugar Company were the biggest winners as its shares went up 4.99% to 353,350 rials per share.
Asan Pardakht Persian Company, Sadr Tamin Investment Company, Zar Macaron Industrial Company, Parsian Oil and Gas Development Company, Takceram Tile Manufacturing Company and National Development Investment Group went down 5% to incurred the biggest losses among all TSE-listed companies
Mobarakeh Steel Company contributed the most to the benchmark's fall, followed by National Iranian Copper Industry Co, Persian Gulf Petrochemical Industries Co, Golgohar Mining and Industrial Company and Ghadir Investment Company.
Behsaz Kashaneh Tehran Company gave the biggest boost to the benchmark index, followed by Neyshabour Sugar Company and Iran Tire Company.
IFX Down 2.04%
Iran Fara Bourse main index, IFX, lost 365.91 points to close Monday trade at 16,973.1.
About 610.4 million securities valued at 17.5 trillion rials ($73m) were traded at the junior exchange for the day.
Marun Petrochemical Company, Arya Sasol Polymer Company, Middle East Mines and Mineral Industries Development Holding Company, Dey Bank and Shahid Tondgooyan Petrochemical Company had the most negative impact on IFX.
Gilan Electric Power Development Company gave the biggest boost to IFX, followed by Peyvand Gostar Pardis, and Tejarat Nou Insurance Company.