Every investor needs an edge. Where better to look than the rules of the world's best investors?These are the do's and don'ts that have driven profits in the billions. They are the practical precepts of many of the best investors in the UK and the US and further afield - the wisdom of the money manager who outperformed the market by staggering percentages for three decades in a row, of the private investor who once trained the professionals in the City, of the ex-hedge fund manager who now advocates the simplest investing system in the world.