Investors should be skeptical of history-based models. Constructed by a nerdy-sounding priesthood using esoteric terms such as beta, gamma, sigma and the like, these models tend to look impressive. Too often, though, investors forget to examine the assumptions behind the models. Beware of geeks bearing formulas.

We will prosper or suffer in controlled investments in relation to the operating performances of our businesses - we will not attempt to profit by playing various games in the securities markets.

When a management with a reputation for brilliance tackles a business with a reputation for bad economics, it is the reputation of the business that remains intact.

Risk is a part of God's game, alike for men and nations.

What an investor needs is the ability to correctly evaluate selected businesses. Note that word “selected”: You don't have to be an expert on every company, or even many. You only have to be able to evaluate companies within your circle of competence. The size of that circle is not very important; knowing its boundaries, however, is vital.

You have to turn over a lot of rocks to find those little anomalies. You have to find the companies that are off the map - way off the map. You may find local companies that have nothing wrong with them at all. A company that I found, Western Insurance Securities, was trading for $3/share when it was earning $20/share!! I tried to buy up as much of it as possible. No one will tell you about these businesses. You have to find them.

Basically, the single-most important decision in evaluating a business is pricing power.