KARACHI: The Pakistan Stock Exchange (PSX) on Wednesday witnessed a volatile session as the index moved both ways, but late value-hunting helped the benchmark index hold minor gains above the key 180,000-point milestone, maintaining a positive close for the third straight session. Topline Securities Ltd said the benchmark KSE-100 index closed marginally higher, settling at 180,511 points, up 118.05 points or 0.07 per cent from the previous close. Despite ending in the green, the market saw significant intraday volatility as investors took profits after the strong rally over the previous two trading sessions.