機會成本（opportunity cost）

閱讀筆記（Notes）：

• Opportunity cost is a popular concept in both economics and finance that states that with every action we take, we give up the benefits of taking an alternative action. In this context, the opportunity cost of investing only in the United States (assuming we can achieve the results of the S&P 500) can be very high. For instance, in 2002 your funds would have returned –22.1 percent if they had been invested only in the S&P 500, and that assumes that you achieved a return as good as that of the S&P 500. Conversely, if you had spread your money evenly throughout these markets, you would have generated a return of –14.5 percent. (摘自Investing the Templeton Way: The Market-Beating Strategies of Value Investing's Legendary Bargain Hunter, by Lauren C. Templeton and Scott Phillips)