If you were to listen to most stock analysts, you'd be excused for concluding that Annaly Capital Management (NLY 0.27%) and American Capital Agency (AGNC -1.61%) are some of the best bargains in the market today. The problem with this perspective, however, is that it's wrong.

The bullish storyline on these stocks is simple: Because both are currently trading for a discount to book value, they must therefore be a bargain -- for the record, Annaly trades for a 7% discount to book value while American Capital Agency's current valuation is 5% less.

But what this storyline seems to miss is that current stock prices don't reflect the present set of facts. Instead, stock prices reflect future expectations. And in this case, the expectation is that these companies' book values are likely to decline going forward.

Is this a realistic expectation? Check out the video below to see why Motley Fool senior banking specialist John Maxfield thinks it is.