Welcome news regarding elevated inflation is prompting signals that there may be a slowdown in the Federal Reserve's pace on interest rate hikes. With longer-term interest rates beginning to fall, mortgage real estate investment trusts (REITs) are once again getting attention from the investment community. Mortgage REITs struggled over the past year as rising rates caused the value of their investment portfolios to decline, which translated into big declines in book value per share.

Surprisingly, these REITs still managed to maintain their dividends, and the yields have become quite attractive (provided they can be maintained). The biggest names in the mortgage REIT space are Annaly Capital (NLY 0.25%) and AGNC Investment (AGNC 0.71%).

Given all the news recently, which one is the better buy right now?

House on top of stacked money next to a calculator.

Image source: Getty Images.

Mortgage REITs are a different animal than the typical REIT

REITs traditionally focus on developing real estate properties such as apartment buildings, office buildings, or shopping malls. They then rent out the units to tenants. Their earnings generally come from the spread between the rents they collect and the interest they pay on the debt that financed the buildings.

Mortgage REITs don't buy properties; they buy real estate debt (i.e. mortgages). They typically use borrowed money to build their portfolios, and their earnings are the difference between the interest they earn on the mortgage-backed securities and the interest they pay on their debt. In many ways, mortgage REITs' operations are closer to a banking model than the landlord/tenant model that characterizes the typical REIT. 

AGNC invests in mortgages guaranteed by the U.S. government

AGNC Investment invests primarily in mortgage-backed securities which are guaranteed by the U.S. government. For the most part, this means AGNC invests in mortgages guaranteed by Fannie Mae and Freddie Mac. Since the principal and interest payments are backed by the U.S. government, AGNC Investment takes very little credit risk, and the interest it earns on these securities tends to be lower. That lower risk also means lower returns. AGNC then uses a lot of borrowed money (think of it like margin on your stock account) to generate a double-digit dividend yield. 

Annaly has a more diversified portfolio of assets

Annaly invests in agency mortgage-backed securities, but it also buys loans that are not guaranteed by the government. These loans pay higher rates of return, but they also tend to have a higher potential for downside. Annaly is a big investor in loans that are ineligible for a government guarantee. These loans are often referred to as non-QM and are often made to professional real estate investors and the self-employed borrower.

These non-QM loans are nothing like the bad old subprime loans of yesteryear. They require sizable down payments and proof that the investor will be able to pay the loans with rental income. So the risk is somewhat mitigated.

Ultimately, the decision on Annaly versus AGNC depends on the economic forecast. AGNC Investment will probably outperform Annaly if we head into a recession, since it won't have to worry about credit losses from the resulting rise in loan defaults. AGNC will also be better protected if housing prices begin to fall. That said, Annaly has a much more diversified portfolio of assets, which helps it outperform in most interest rate environments.

However, Annaly will be more exposed to potential credit losses if the economy enters a recession. If housing prices fall, it will negatively affect the value of its non-QM loans if delinquencies begin to increase. Annaly also holds a large mortgage servicing portfolio, which is a stable source of additional income and acts as a hedge if interest rates rise. 

Watch the book value per share

At current levels, AGNC Investment is trading right around book value per share of $10.04 and has a dividend yield of 14.4%. A bet on Annaly is a bet on a drop in interest rate volatility, which will probably happen once the Fed ends its tightening cycle.

Annaly is trading at a premium to its book value per share of $19.94; however, it has a better dividend yield of 16.6%. As a general rule, mortgage REITs trade right around book, so it usually pays to buy them at a discount to book, not a premium.

Despite Annaly's higher yield, I like AGNC better, as home prices are beginning to decline, which will weigh on Annaly's credit-sensitive book. I also don't like buying mortgage REITs above book value. All this means I think AGNC Investment is the better buy at the moment.