Investing in big banks can be intimidating. It's often unclear how these massive institutions make their money, but as financial editor Matt Koppenheffer reveals, there are a few relatively straightforward revenue streams at these companies today that even Joe and Jane investor can understand. 

Matt Koppenheffer owns shares of Bank of America and Regions Financial. The Motley Fool recommends Wells Fargo. The Motley Fool owns shares of Bank of America, Citigroup, JPMorgan Chase, KeyCorp, and Wells Fargo. 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.