In gardening, a hedge is a line of shrubs which forms a barrier between two areas. In finance, a hedge is a risk management strategy based on making investments or business plans in such a way that a loss in one area of the portfolio will be balanced by a gain in another area of the portfolio. For example, Southwest Airlines correctly predicted, a few years ago, that the price of jet fuel was going to rise dramatically. Normally, this would hurt their business. However, they used this prediction...