Hedge funds and other investors now stand to make billions from their holdings in bankrupt US mall owner General Growth Properties amid the recent rebound in financial markets. Among the biggest potential winners is William Ackman’s Pershing Square Capital Management, which is sitting on a paper profit of more than $800m on investments in the debt and equity of GGP, say people familiar with the fund. Other investors likely to profit on their GGP holdings include Centerbridge Partners, Elliott Associates, Goldman Sachs, Paulson & Co and York Capital.