In a yield-starved environment, mREITs sporting double-digit dividends have caught the attention of many investors. One company that has grown extremely fast during the Fed's QE programs is American Capital Agency (NASDAQ:AGNC).

The mREIT's asset balance has ballooned during the past several years, and investors saw huge total returns during that time. However, the mortgage-backed securities on its books lost value in the most recent quarter. Is this a concern?

In this video, Motley Fool financial analyst David Hanson reminds investors of the relationship between the dividend and the balance sheet and why investors should be asking themselves a few questions.