Shares at the Pakistan Stock Exchange (PSX) reversed major gains on Monday as the KSE-100 index shed more than 2,000 points on International Monetary Fund (IMF) concerns over electricity tariffs. The benchmark KSE-100 index shed 2,002.55 points, or 1.69 per cent, to stand 116,439.62 from the last close of 118,442.17 points. Topline Securities, a brokerage firm in Karachi, noted that the mark