The secret of sound investing can be distilled into three words, margin of safety. Investment is most intelligent when it is most businesslike. Your goal as an investor should be simply to purchase, at a rational price, a part interest in an easily understood business whose earnings are virtually certain to be materially higher, five, ten and twenty years from now. Over time, you will find only a few companies that meet those standards – so when you see one that qualifies, you should buy a meaningful amount of stock.