Do not accept principal risk while investing short-term cash: the greedy effort to earn a few extra basis points of yield inevitably leads to the incurrence of greater risk, which increases the likelihood of losses and severe illiquidity at precisely the moment when cash is needed to cover expenses, to meet commitments, or to make compelling long-term investments.

It is important to remember that value investing is not a perfect science. It is an, with an ongoing need for judgment, refinement, patience, and reflection. It requires endless curiosity, the relentless pursuit of additional information, the raising of questions, and the search for answers. It necessitates dealing with imperfect information - knowing you will never know everything and that that must not prevent you from acting. It requires a precarious balance between conviction, steadfastness in the face of adversity, and doubt - keeping in mind the possibility that you could be wrong.

Below, we itemize some of the quite different lessons investors seem to have learned as of late 2009 - false lessons, we believe. To not only learn but also effectively implement investment lessons requires a disciplined, often contrary, and long-term-oriented investment approach. It requires a resolute focus on risk aversion rather than maximizing immediate returns, as well as an understanding of history, a sense of financial market cycles, and, at times, extraordinary patience.

Rather, risk is a perception in each investor's mind that results from analysis of the probability and amount of potential loss from an investment. If an exploratory oil well proves to be a dry hole, it is called risky. If a bond defaults or a stock plunges in price, they are called risky. But if the well is a gusher, the bond matures on schedule, and the stock rallies strongly, can we say they weren't risky when the investment after it is concluded than was known when it was made.

Speculators are obsessed with predicting: guessing the direction of stock prices. Every morning on cable television, every afternoon on the stock market report, every weekend in Barron's, every week in dozens of market newsletters, and whenever business people get together. In reality, no one knows what the market will do; trying to predict it is a waste of time, and investing based upon that prediction is a purely speculative undertaking.

Occasionally we are asked whether it would make sense to modify our investment strategy to perform better in today's financial climate. Our answer, as you might guess, is: No! It would be easyfor us to capitulate to the runaway bull market in growth and technology stocks. And foolhardy. And irresponsible. And unconscionable. It is always easiest to run with the herd; at times, it can take a deep reservoir of courage and conviction to stand apart from it. Yet distancing yourself from the crowd is an essential component of long-term investment success.

Short sellers age in dog years.