伊索三问定价值；安全边际防错；留下的每一美元，须创造超过一美元的价值。
英文为原文摘录；中文标「译文」。点击年份打开本站 letters/ 中的官方文件。
“The oracle was Aesop and his enduring, though somewhat incomplete, investment 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 (which we consider to be the yield on long-term U.S. bonds)?”译文 先知是伊索：一鸟在手胜过二鸟在林。充实这条原则只需三问——林中是否确有鸟？何时出现、有几只？无风险利率是多少？
“If we calculate the value of a common stock to be only slightly higher than its price, we're not interested in buying. We believe this margin-of-safety principle, so strongly emphasized by Ben Graham, to be the cornerstone of investment success.”译文 若算出的价值仅略高于价格，我们就没有兴趣买。格雷厄姆强调的安全边际，是投资成功的基石。
flowchart TB
V[内在价值] --> Q1[几只鸟?]
V --> Q2[何时?]
V --> Q3[利率?]
V --> P[市价]
P --> M{安全边际?}
M -->|够| Buy[配置]
M -->|不够| Wait[等待]
示意图是阅读辅助，不是巴菲特原图。