In this edition of The Motley Fool's "Ask a Fool" series, Motley Fool analysts Jason Moser and Brendan Mathews take a question from a reader who asks, "How many companies should I own?"

Brendan starts by suggesting that investors own at least 15 companies. That will allow at least a minimum amount of diversification. Beyond that, it really depends on the investor's situation and preferences. Some investors like to own a lot of stocks to increase their diversification. Others like to focus on their best ideas. That's how Jason likes to invest, and he describes why.

Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.