Philip Fisher on Mistakes & Learning

Members of Fisher's family later recalled that his 1987 sale was not a valuation call but a recognition of what portfolio insurance and program trading were doing to market behavior. The lesson his son Kenneth drew from it was about humility under regime change: a framework built in one market structure may need to be suspended when the structure itself mutates.

Fisher's grandson Ken Fisher has written that Philip regretted aspects of the timing but never the logic of reassessing everything after a structural break. The incident is usually cited as a counterpoint to the caricature of growth investors as permanent holders, and as evidence that Fisher treated his fifteen points as tools of judgment, not a religion.

In his late-career monograph, Fisher recounted how the 1929 era taught him to distrust market tips and crowd enthusiasm. A credit analyst job in his early twenties exposed him to good and bad managements, and he concluded that the durable lessons of investing came from studying exceptional businesses at close range rather than from market forecasting.

Fisher considered the error rate of trying to time the market on great companies far worse than the cost of holding them through declines. He wrote that the money was made not by buying and selling but by owning — by sitting through the volatility that shook out less committed holders. At the same time he was ruthless about cutting genuine analytical mistakes, arguing that the refusal to admit an error was the most expensive habit an investor could have.