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.

A tipping point is invisible, as we just saw in Greece. In most situations, everything appears fine until it's not fine, until, for example, no one shows up at a Treasury auction.

It is crucial to have a strategy in place before problems hit, precisely because no one can accurately predict the future direction of the stock market or economy. Value investing, the strategy of buying stocks at an appreciable discount from the value of the underlying businesses, is one strategy that provides a road map to successfully navigate not only through good times but also through turmoil.

You need humility to say 'I might be wrong.'

The risk of an investment is described by both the probability and the potential amount of loss. The risk of an investment-the probability of an adverse outcome-is partly inherent in its very nature. A dollar spent on biotechnology research is a riskier investment than a dollar used to purchase utility equipment. The former has both a greater probability of loss and a greater percentage of the investment at stake.

There's no such thing as a value company. Price is all that matters. At some price, an asset is a buy, at another it's a hold, and at another it's a sell.

As Graham, Dodd and Buffett have all said, you should always remember that you don't have to swing at every pitch. You can wait for opportunities that fit your criteria and if you don't find them, patiently wait. Deciding not to panic is still a decision.