Listen to Buffett: “The formula we use for evaluating stocks and businesses is identical. Indeed, the formula for valuing all assets that are purchased for financial gain has been unchanged since it was first laid out by a very smart man in about 600 B.C.E. The oracle was Aesop, and his enduring, though somewhat incomplete, insight was ‘a bird in the hand is worth two in the bush.’ To flesh out this principle, you must answer only three questions. How certain are you that there are indeed birds in the bush? When will they emerge, and how many will there be? What is the risk-free interest rate? If you can answer these three questions, you will know the maximum value of the bush—and the maximum number of birds you now possess that should be offered for it. And, of course, don’t literally think birds. Think dollars.”我非常确定，伊索在2600年前写下“鹰与夜莺”的时候，他并没有意识到这是投资界的一条金科玉律。
听巴菲特是怎么说的：“我们用来评估股票和企业的公式是相同的。事实上，自大约公元前600年一位非常聪明的人首次提出以来，用于评估所有金融资产的公式从未改变过。这位神谕是伊索，他持久但有些不完整的洞见是‘手中的鸟价值林中的两只鸟’。要完善这个原则，你必须回答三个问题。你确定树林里真的有鸟吗？它们什么时候出现？会有多少只？无风险利率是多少？如果你能回答这三个问题，你就会知道树林的最大价值——以及你现在拥有的、应该为它提供的最大数量的鸟。当然，不要真的去想鸟。想想美元。