The main index of Tehran Stock Exchange, TEDPIX, lost 22,363 points, or 1.77%, to close Sunday at 1,240,523 points, the lowest since June 20.
With sale orders worth trillions of rials unprocessed due to lack of buyers, retail trade value declined to a 10-month low.
Total trade value reached 40.91 trillion rials ($163 million) in both the TSE and junior equity market Iran Fara Bourse, down by 47% compared to the day earlier.
Retail trade value was 21.5 trillion rials ($86m), 50.5% lower than the day before and the lowest since Jan 10. Retail traders fled the market with capital outflow worth 5.49 trillion rials ($22m).
Citing market observers, the Persian-language economic newspaper Donya-e-Eqtesad likened the market investors' heightened nervousness to the decline in inflation expectation due to a weaker dollar.
Declining foreign exchange rates means lower income for most export companies in the bourse holding 60% of Iran's share market.
TSE Trade
About 2.34 billion shares valued at 22.91 trillion rials ($97.5 m) changed hands at TSE for the day. Ama Industrial Company was the biggest winner as its shares went up 4.98% to 25,920 rials per share.
Vehicle Axle Manufacturing Company incurred the biggest loss among all TSE-listed companies and went down 5.57% to 55,310 rials per share.
National Iranian Copper Industries Company contributed the most to the benchmark's fall, followed by Golgohar Mining and Industrial Company, Mobarakeh Steel Company and Iran Khodro Company.
Dr. Abidi Pharmaceutical Company gave the biggest boost to the benchmark index followed by Tamin Pharmaceutical Investment Company, Ama Industrial Company and Shafa Darou Investment Company.
IFX Down 1.72%
Iran Fara Bourse main index, IFX, lost 273.73 points, or 1.72%, to close Sunday trade at 15,617.99.
About 838.62 million securities valued at 18.01 trillion rials ($76.64m) were traded at the junior exchange for the day.
Arya Sasol Polymer Company, Middle East Mines and Mineral Industries Development Holding Company, Gohar Zamin Iron Ore Company and Zagros Petrochemical Company had the most negative impact on IFX.
Minoo Industrial Group Company gave the biggest boost to IFX, followed by Taliseh Nemooneh Dairy Farm Company, Caspian Tamin Pharmaceutical Company and Alborz Distribution Company.