Zarif announced his resignation in an Instagram post late Monday. It is not known yet whether President Hassan Rouhani had accepted the resignation.
The market rout came amid growing optimism amid investors that had led to a three-day winning streak up until Monday. The key market gauge rose 128.84 points on Sunday and on Saturday TEDPIX grew 4,778.26 or 3.00% which was the biggest single-session point gains for the market in four months.
However all that came crashing down after Zarif's sudden decision to step down brought new uncertainly about the country's future relations with the outside world, according to Financial Tribune.
As reported by Donyaye Bourse website, another shock which rattled stock investors was President Donald Trump's tweet which took aim at high world oil prices. Robust oil prices had been a key reason for the rise of commodity stocks in Iran.
Oil prices tumbled more than 3% on Monday after Trump publicly urged OPEC to lower the cost of crude, putting pressure on the Saudi-led group to soften its price-boosting output cuts.
"Oil prices getting too high. OPEC, please relax and take it easy. World cannot take a price hike - fragile!" the US president said in an early morning tweet.
Esfahan Oil Refining Company, Mobarakeh Steel Company, Tehran Oil Refining Company and Bandar Abbas Oil Refining Company had the biggest negative impact on the main index on Tuesday.