Can a financials-focused portfolio with stocks like Bank of America (BAC -0.27%), AIG (AIG -0.44%), and Realty Income (O 0.29%) leave investors too exposed to one sector? In this segment from The Motley Fool's everything-financials show, Where the Money Is, banking analysts David Hanson and Matt Koppenheffer take a question from their mailbag about diversification within a broader sector. David highlights that despite what happened during the financial crisis, financial stocks may not always perform the same way.