KARACHI: The Pakistan Stock Exchange (PSX) witnessed sharp volatility on Tuesday, but last-hour value-hunting helped the benchmark KSE-100 index close in the green for a second consecutive session. Market nervousness stemmed from a fragile US-Iran ceasefire following a day of clashes involving shipping in the Strait of Hormuz and missile strikes targeting the UAE. Topline Securities Ltd said the benchmark index saw a mixed and volatile session, touching an intraday low of 1,415 points and a high of 971 points, before settling at 164,742.47, up 793.53 points or 0.48 per cent), amid persistent uncertainty over US-Iran developments.