For me anything under $15 is a buy. With a 13% dividend you should plan on holding it for the long term(5 to 10 yrs). When the spreads on interest rates widens this company will do well. If they announce a solid dividend this qtr I expect the stock to go over $14 within a couple of days. Good luck.
I have held NLY for several years. I'm not sure what my average basis is, because I have it spread over several accounts and too lazy to calculate it, but I'm sure it is higher than 13 and change, so I'm hurting right now. However, I think the dividend has a good chance of staying about the same because the spread should be increasing with short interest rates staying low and mortgage rates going up. Of course, the book value is plummeting, but unless NLY ineptly decides to sell some mortgages and lock in losses, there is no reason their income should fall.
The stock price "should" reflect expectations of the dividends, and book value is practically irrelevant, but folks have their valuation templates that might not fit such an odd duck as NLY.
We should find out pretty soon if the dividend holds up.