Buffett’s “circle of competence” rule can help you avoid costly mistakes—but it’s often misunderstood by everyday investors.

According to Buffett, investors don’t need to predict the next big thing; they need to know their own strengths and stick to them. Buffett’s formula for success is clear: An investor needs the ability ...

Warren Buffett advises investors to only buy assets they fully understand. Buffett recommends S&P 500 index funds for most retirement savers because they’re simple and easy to manage. Staying within ...