Shares at the Pakistan Stock Exchange (PSX) on Thursday witnessed selling pressure, shedding more than 500 points. The benchmark KSE-100 index declined by 589.95 points, 0.72 per cent, to close at 81,657.96 points from the previous close of 82,247.91 points. However, it is important to note that the index hit a life-time high in opening trade, rising to a record high of 82,905.73 points befo