Successful investors like stocks better when they’re going down. When you go to a department store or a supermarket, you like to buy merchandise on sale, but it doesn’t work that way in the stock market. In the stock market, people panic when stocks are going down, so they like them less when they should like them more. When prices go down, you shouldn’t panic, but it’s hard to control your emotions when you’re overextended, when you see your net worth drop in half and you worry that you won’t have enough money to pay for your kids’ college.

There are only a few things investors can do to counteract risk: diversify adequately, hedge when appropriate, and invest with a margin of safety. It is a precisely because we do not and cannot know all the risks of an investment that we strive to invest at a discount. The bargain element helps to provide a cushion for when things go wrong.

Depressions aren't good but the depression mentality is good.

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.

Selling, in particular, can be a challenge; many investors are tempted to become more optimistic when a security is performing well. This temptation must be resisted; tax considerations aside, when a security reaches full valuation, there is no longer a reason to own it.

Literally draw a detailed map-like an organization chart-of interlocking ownership and affiliates, many of which were also publicly traded. So, identifying one stock led him to a dozen other potential investments. To tirelessly pull threads is the lesson that I learned from Mike Price.

Short-term performance envy causes many of the shortcomings that lock most investors into a perpetual cycle of underachievement. Watch your competitors not out of jealousy but out of respect and focus your efforts not on replicating others' portfolios but on looking for opportunities where they are not. The only way for investors to significantly outperform is to periodically stand far apart from the crowd, something few are willing, or able, to do.