Istanbul's stock exchange operator said the market would be closed for five days, and that all trades that took place on Wednesday would be cancelled in the wake of two devastating earthquakes that struck Turkiye and Syria on Monday.
The benchmark index has slid some 14% since Monday, with trading volumes significantly below regular averages at only 2.24 billion trades on Tuesday, a little over half of Friday's 4.14 billion.
"Due to the increase in volatility and extraordinary price movements after the earthquake disaster; in order to ensure the reliable, transparent, efficient, stable, fair and competitive functioning of the markets, Equity Market and Equity&Index Derivatives in the Derivatives Market have been closed," read Borsa Istanbul's statement on Wednesday.
"Considering the low transaction volume that does not allow efficient price formation, all trades executed in the closed markets on Feb. 8, 2023 will be cancelled," the market operator said.
Some Turkish investors urged the reversal of all trades that took place on the bourse following the earthquakes.
Turkey's Borsa Istanbul suspended trading on its equity and derivatives markets within 90 minutes of opening after two market-wide circuit breakers failed to stop a 7% slide in the main index.
Following the quakes, which forced major corporations like BP to declare force majeure in their disaster zone operations, domestic investors started an online petition calling for the reversal of all trades that took place on and after Monday.
"We call for the reversal of all trades that took place on Borsa Istanbul as of February 6, 2023 and the closure of the exchange during the national mourning period," read the statement accompanying the petition.
The petition received over 5,000 signatures within hours, nearing its goal for a total of 7,500.
Domestic investors have flooded Istanbul's stock market in the past year in efforts to hedge against inflation, prompting the market to soar nearly 200%.
Main opposition member of parliament Murat Bakan said on Twitter: "Suspending the exchange is not enough. Trades that took place on Istanbul stock exchange following the earthquake must be cancelled."
The reversal of trades will protect the rights of 500,000 investors, Bakan said, adding that some people might still be awaiting help or not have internet access in ten cities following the quakes that killed more than 8,500 people.