A sharp rise in the price of Fortescue Metal Group shares has increased Andrew "Twiggy" Forrest's personal fortune by around half a billion dollars within the space of two days.

Andrew Forrest appears to have already cashed in on the positive karma reaped from his recent, record-breaking act of philanthropy, with prices in Fortescue shares surging 43 cents in the space of just two trading sessions. As a result of the price spike the value of Forrest’s personal holdings in…