Everyone has the brainpower to make money in stocks. Not everyone has the stomach. If you are susceptible to selling everything in a panic, you ought to avoid stocks and mutual funds altogether.

I'm always fully invested. It's a great feeling to be caught with your pants up.

All you need for a lifetime of successful investing is a few big winners, and the pluses from those will overwhelm the minuses from the stocks that don't work out.

The worst thing you can do is invest in companies you know nothing about. Unfortunately, buying stocks on ignorance is still a popular American pastime.

There's no use diversifying into unknown companies just for the sake of diversity. A foolish diversity is the hobgoblin of small investors. That said, it isn't safe to own just one stock, because in spite of your best efforts, the one you choose might be the victim of unforeseen circumstances. In small portfolios, I'd be comfortable owning between three and ten stocks.

If you're prepared to invest in a company, then you ought to be able to explain why in simple language that a fifth grader could understand, and quickly enough so the fifth grader won't get bored.

I like to buy a company any fool can manage because eventually one will.