The Pakistan Stock Exchange’s (PSX) benchmark index KSE-100 shed 6,600 points on Monday in a turbulent session, after weekend peace talks between the United States and Iran failed and the US president ordered a blockade of Iranian ports.

The KSE-100 index opened on a low note of around 161,000 points, compared to the previous close of 167,191.37.

The market fluctuated throughout the session, reaching an intraday high of 163,612.11 points at 12:13pm and then an intraday low of 160,158.92 points at 2:56pm.

It then finally closed at 160,591.33 points, down 6,600.04 points or 3.95pc.

In a post on the social media platform X, Topline Securities said the benchmark index registered a sharp decline in a “highly volatile trading session”.

“The market witnessed significant fluctuations throughout the day, with the index reaching an intraday high of 163,612 points and slipping to a low of 160,158 points,” it said.

“The downturn was primarily driven by uncertainty surrounding the lack of progress in the US–Iran talks held in Islamabad, coupled with growing concerns over a potential blockade of the Strait of Hormuz,” it said, adding that these developments pushed global oil prices higher, triggering broad-based panic selling across the market.

“Selling pressure was particularly concentrated in index-heavy stocks, with FFC, UBL, ENGROH, LUCK, and MEBL emerging as major laggards, collectively pulling the benchmark down by 2,414 points,’“ Topline Securities said.

“Trading activity remained strong, with total traded volume reaching 743 million shares and overall turnover amounting to Rs34.2 billion,” it said.

After Washington and Tehran failed to reach an agreement in the marathon peace talks held in Islamabad, US President Donald Trump said the US Navy would begin the process of blockading vessels entering or leaving the Strait of Hormuz.

Hormuz, a key shipping lane off the coast of Iran, has been virtually blocked by Tehran since the US and Israel started bombing Iran on February 28, though reopening the strait was ostensibly a condition of the ceasefire put in place on April 8.

Iran’s Islamic Revolutionary Guards Corps (IRGC) said that any military vessels attempting to approach the Strait of Hormuz would be considered a ceasefire violation, warning that it would be dealt with harshly and decisively.

The PSX has witnessed huge single-day losses since the US-Israel war on Iran began. It had witnessed the steepest single-day plunge, shedding 16,089 points (or 9.57pc), on March 2 following the assassination of Iran’s supreme leader Ayatollah Ali Khamenei.