FT.com – Porsche this month revealed it had made EU3.6bn from share options in the year to July, compared with about EU1bn from sales of its cars. The news provoked comments from some analysts that the German luxury marque was acting more like a hedge fund than a carmaker. Yet many managers regard derivatives as essential tools to manage the risks of volatility in exchange rates, interest rates and commodity prices. When is it acceptable for manufacturers to place big bets on the market? Should investors be pleased or dismayed when an industrial enterprise makes money from financial speculation?