An important key to investing is to remember that stocks are not lottery tickets.

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.

It isn't the head but the stomach that determines the fate of the stockpicker.

You can't see the future through a rearview mirror

Never invest in any idea you can't illustrate with a crayon

I think you have to learn that there's a company behind every stock, and that there's only one real reason why stocks go up. Companies go from doing poorly to doing well or small companies grow to large companies.

When management owns stock, then rewarding the shareholders becomes a first priority, whereas when management simply collects a paycheck, then increasing salaries becomes a first priority.