A simple rule applies: if you don't quickly comprehend what a company is doing, then management probably doesn't either.

In a world in which most investors appear interested in figuring out how to make money every second and chase the idea du jour, there's also something validating about the message that it's okay to do nothing and wait for opportunities to present themselves or to pay off. That's lonely and contrary a lot of the time, but reminding yourself that that's what it takes is quite helpful.

The single greatest edge an investor can have is a long-term orientation.

We buy expecting to hold a bond to maturity and a stock forever.

In a rising market, everyone makes money and a value philosophy is unnecessary. But because there is no certain way to predict what the market will do, one must follow a value philosophy at all times.

The avoidance of loss is the surest way to ensure a profitable outcome.

Unlike return, however, risk is no more quantifiable at the end of an investment that it was at its beginning. Risk simply cannot be described by a single number. Intuitively we understand that risk varies from investment to investment: a government bond is not as risky as the stock of a high-technology company. But investments do not provide information about their risks the way food packages provide nutritional data.