From The Most Important Thing:
I think it’s essential to remember that just about everything is cyclical. There’s little I’m certain of, but these things are true: Cycles always prevail eventually. Nothing goes in one direction forever. Trees don’t grow to the sky. Few things go to zero. And there’s little that’s as dangerous for investor health as insistence on extrapolating today’s events into the future.
In investing, as in life, there are very few sure things. Values can evaporate, estimates can be wrong, circumstances can change and “sure things” can fail. However, there are two concepts we can hold to with confidence:
- Rule number one: most things will prove to be cyclical.
- Rule number two: some of the greatest opportunities for gain and loss come when other people forget rule number one.Very few things move in a straight line. There’s progress and then there’s deterioration. Things go well for a while and then poorly. Progress may be swift and then slow down. Deterioration may creep up gradually and then turn climactic. But the underlying principle is that things will wax and wane, grow and decline. The same is true for economies, markets and companies: they rise and fall.
The basic reason for the cyclicality in our world is the involvement of humans. Mechanical things can go in a straight line. Time moves ahead continuously. So can a machine when it’s adequately powered. But processes in fields like history and economics involve people, and when people are involved, the results are variable and cyclical. The main reason for this, I think, is that people are emotional and inconsistent, not steady and clinical.
Objective factors do play a large part in cycles, of course— factors such as quantitative relationships, world events, environmental changes, technological developments and corporate decisions. But it’s the application of psychology to these things that causes investors to overreact or underreact, and thus determines the amplitude of the cyclical fluctuations.