The TSE's main index TEDPIX lost 728.52 points or 0.34% on Wednesday to end trading week at 211,017.9.
About 3.8 billion shares valued at 12.91 trillion rials ($86.70 million) changed hands at TSE for the day.
Trading at TSE and over-the-counter Iran Fara Bourse starts on Saturday and ends Wednesday, according to Financial Tribune.
Behran Oil Company was the biggest winner as its shares went up 15.58% to 20,145 rials.
Iran Credit Investment Company incurred the biggest loss among all TSE-listed companies and went down 4.98% to 3,247 rials per share.
Persian Gulf Petrochemical Industries Company contributed the most to the benchmark's fall, followed by Mobarakeh Steel Company, Golgohar Mining and Industrial Complex, and Mapna Group.
Mobarakeh Steel Company is the biggest steel producer in Middle East and Northern Africa. The company produces more than 50% of Iran’s steel in major markets including automotive, construction, household appliances and packaging.
Behran Oil Company gave the biggest boost to the benchmark index, followed by Sepahan Oil Company, and Mines and Metal Development Investment Company.
The Price Index lost 208.87 points to close at 60,511.0.
The First Market Index was down 576.40 points to post 158,372.6. Second Market Index decreased by 1,261.56 points to reach 406,455.4.
The Industry Index went down by 700.69 points to register 189,567.3. Free Float Index was down 194.59 points to hit 237,106.22.
TSE 30 went down 97.49 points to settle at 9,894.1 and the TSE 50 ended 48.61 points lower to finish at 8,737.4.
Iran Fara Bourse’s main index IFX lost 4.65 points or 0.18% to close Wednesday trade at 2,583.46.
About 1.42 billion shares and securities valued at 7.54 trillion rials ($50.69 million) were traded at the over-the-counter exchange for the day.