KARACHI, July 29: A decision taken by the Adviser to the PM on Finance, Dr Salman Shah, on Friday would enhance the investors’ capacity to trade in stocks using margin finance. That, in turn, should lift the sagging stock market that has been under a crisis of liquidity since the middle of March this year after scaling dizzying heights. Dr Salman Shah told Dawn on Friday that he had asked the stock exchange management to eliminate the double margin requirement in margin financing within 48 hours.