Figure out what something is worth and pay a lot less.

There’s a virtuous cycle when people have to defend challenges to their ideas. Any gaps in thinking or analysis become clear pretty quickly when smart people ask good, logical questions. You can’t be a good value investor without being an independent thinker – you’re seeing valuations that the market is not appreciating. But it’s critical that you understand why the market isn’t seeing the value you do. The back and forth that goes on in the investment process helps you get at that.

If I plug my estimates into the Magic Formula, and it comes out cheap, that's good.

Over the long term, despite significant drops from time to time, stocks (especially an intelligently selected stock portfolio) will be one of your best investment options. The trick is to GET to the long term. Think in terms of 5 years, 10 years and longer. Do your planning and asset allocation ahead of time. Choose a portion of your assets to invest in the stock market - and stick with it! Yes, the bad times will come, but over the truly long term, the good times will win out - and I hope the lessons from 2008 will help get you there to enjoy them.

Value investing doesn't always work. The market doesn't always agree with you. Over time, value is roughly the way the market prices stocks, but over the short term, which sometimes can be as long as two or three years, there are periods when it doesn't work. And that is a very good thing. The fact that our value approach doesn't work over periods of time is precisely the reason why it continues to work over the long term.

Something out of the ordinary course of business is taking place that creates an investment opportunity. The list of corporate events that can result in big profits for you runs the gamut—spinoffs, mergers, restructurings, rights offerings, bankruptcies, liquidations, asset sales, distributions.

The secret to investing is to figure out the value of something - and then pay a lot less.