Investing is the intersection of economics and psychology. The analysis is actually the easy part. The economics, the valuation of the business isn't that hard. The psychology - how much do you buy, do you buy it at this price, do you wait for a lower price, what do you do when it looks like the world might end - those things are harder. Knowing whether you stand there, buy more, or whether something has legitimately gone wrong and you need to sell, those are harder things. That you learn with experience, by having the right psychological makeup.

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

My view is that an investor is better off knowing a lot about a few investments than knowing a little about each of a great many holdings. One's very best idea's are likely to generate higher returns for a given level of risk than one's hundredth or thousandth best idea.

Value investing requires a great deal of hard work, unusually strict discipline, and a long-term investment horizon. Few are willing and able to devote sufficient time and effort to become value investors, and only a fraction of those have the proper mind-set to succeed.

When a Wall Street analyst or broker expresses optimism, investors must take it with a grain of salt.

When you buy bargains and they become better bargains, it is easy to start to question yourself, which can impair your judgement. Real or imagined concerns about client redemptions, employee defections can greatly influence behavior away from rational.

There is no amount of bad news that the markets cannot see past.