When excesses such as lax lending standards become widespread and persist for some time, people are lulled into a false sense of security, creating an even more dangerous situation. In some cases, excesses migrate beyond regional or national borders, raising the ante for investors and governments. These excesses will eventually end, triggering a crisis at least in proportion to the degree of the excesses. Correlations between asset classes may be surprisingly high when leverage rapidly unwinds.

Wall Street can be a dangerous place for investors. You have no choice but to do business there, but you must always be on your guard. The standard behavior of Wall Streeters is to pursue maximization of self-interest; the orientation is usually short term. This must be acknowledged, accepted, and dealt with. If you transact business with Wall Street with these caveats in mind, you can prosper. If you depend on Wall Street to help you, investment success may remain elusive.

Ratings agencies are highly conflicted, unimaginative dupes. They are blissfully unaware of adverse selection and moral hazard. Investors should never trust them.

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.

There is an old saying, "How did you go bankrupt?" And the answer is, "Gradually, and then suddenly." The impending fiscal crisis in the United States will make its appearance in the same way.

Value investors will not invest in businesses that they cannot readily understand or ones they find excessively risky. Hence few value investors will own the shares of technology companies. Many also shun commercial banks, which they consider to have unanalyzable assets, as well as property and casualty insurance companies, which have both unanalyzable assets and liabilities.

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.