Cautious sentiment engulfed the Pakistan Stock Exchange (PSX) on Monday, pulling the KSE-100 Index down 404.24 points, or 0.24%, to 170,360.98 by 12:38pm as uncertainty over a United States-Iran diplomatic breakthrough weighed on risk appetite.

The index had opened the week on a positive note, climbing to 171,038.58, up 273.36 points, or 0.16%, by 9:33am. However, profit-taking soon erased the early gains, with the market turning volatile and moving lower.

Read: PSX reverses gains as geopolitics weigh

The pressure came as Brent crude prices rebounded more than 3% in Asian trading after US President Donald Trump rejected an Iranian proposal aimed at resolving the conflict and reopening the Strait of Hormuz, keeping tensions in the Middle East elevated.

The KSE-100 opened higher and climbed to an intraday high of 171,126.52 before reversing course. It fell to a low of 170,120.49 during the session, while 53.14 million shares changed hands with traded value reaching Rs4.02 billion.