KARACHI: The benchmark index of the Pakistan Stock Exchange (PSX) continued its upward momentum on Thursday to cross the 64,000 milestone in yet another record high. According to the PSX website, the KSE-100 index gained 380.55 points at 10:20am to reach 64,298.27, up 0.6 per cent from the previous close of 63,917.72. The benchmark of representative shares, maintaining its bull …