The main gauge of Tehran Stock Exchange, TEDPIX, shed 10,420.55 points and slipped 0.71% to finish trading at 1,455,610.
The TSE’s equal-weighted index, which better reflects the performance of small caps, lost 1.4% amid unrelenting sell-side pressure in penny stocks.
As the session closed, 401 tickers were in negative territory, accounting for 81% of the total tickers.
Net capital outflow by retail investors continued for five straight sessions, reaching 4.66 trillion rials ($17 million) on Sunday.
Value of retail trade dropped 10% to reach 51.6 trillion rials ($191m), indicating lower liquidity of shares. About 4.95 billion shares valued at 45.21 trillion rials ($167m) changed hands at TSE for the day.
Trading at the TSE and the junior exchange Iran Fara Bourse starts on Saturday and ends Wednesday.
Sepanta Communication Development Company was the biggest winner as its shares went up 4.92% to 490,070 rials per share.
Khazar Cement Company incurred the biggest loss among all TSE-listed companies and went down 4.99% to 24,380 rials per share.
National Iranian Copper Industries Company contributed the most to the benchmark's fall, followed by Mobarakeh Steel Company, Mobile Telecommunication Company of Iran and Pardis Petrochemical Company.
Tamin Petroleum and Petrochemical Investment Company gave the biggest boost to the benchmark index followed by Parsian Oil and Gas Development Group Company, Tabriz Oil Refining Company and Mobin Energy Persian Gulf Company.
IFB Down 0.9%
Iran Fara Bourse main index, IFX, lost 197.52 points or 0.94% to close Sunday trade at 20,782. About 2.46 billion securities valued at 181.45 trillion rials ($672m) were traded at the junior exchange for the day.
Day Bank had the highest number of traded shares as 565.64 million of its shares worth 580.25 billion rials ($2.2m) were traded.
Arya Sasol Polymer Company, Pasargad Insurance Company, Sirjan Jahan Steel Complex and Iran Fara Bourse had the most negative impact on IFX.
Shiraz Oil Refining Company gave the biggest boost to IFX, followed by Lavan Oil Refining Company, Pasargad Oil Company and Zagros Petrochemical Company.