Warren Buffett on Business: Principles from the Sage of Omaha

15.2. Mistake Du Jour

In the 1989 annual report I wrote about "Mistakes of the First 25 Years" and promised you an update in 2015. My experiences in the first few years of this second "semester" indicate that my backlog of matters to be discussed will become unmanageable if I stick to my original plan. Therefore, I will occasionally unburden myself in these pages in the hope that public confession may deter further bumblings. (Post-mortems prove useful for hospitals and football teams; why not for businesses and investors?)

Typically, our most egregious mistakes fall in the omission, rather than the commission, category. That may spare Charlie and me some embarrassment, since you don't see these errors; but their invisibility does not reduce their cost. In this mea culpa, I am not talking about missing out on some company that depends upon an esoteric invention (such as Xerox), high-technology (Apple), or even brilliant merchandising (Wal-Mart). We will never develop the competence to spot such businesses early. Instead I refer to business situations that Charlie and I can understand and that seem clearly attractive—but in which we nevertheless end up sucking our thumbs rather than buying.

Every writer knows it helps to use striking examples, but I wish the one I now present wasn't quite so dramatic: In early 1988, we decided to buy 30 million shares (adjusted for a subsequent split) of Federal National Mortgage Association (Fannie Mae), which would have been a $350–$400 million ...