Even after beating the market in 2013, many investors still think big banks like Bank of America and Citigroup are deeply undervalued and stand to benefit from an improving U.S. economy.

In this segment of The Motley Fool's financials-focused show, Where the Money Is, banking analysts Matt Koppenheffer and David Hanson dip into their mailbag to answer a listener's question about investing in a financial-focused ETF like the Financial Select Sector SPDR (XLF 1.24%) instead of picking individual banks.