With the Federal Reserve continuing its efforts to normalize U.S. monetary policy, plenty of asset classes could be affected by those plans, including mortgage-backed securities (MBS) and exchange traded funds such as the iShares MBS ETF (NYSEArca: MBB).
MBS are created when an entity acquires a bundle of mortgages and then sells the securities. Most MBS are seen as a “pass-through” security where the principal and interest payments are passed through the issuer to the investor.
Most funds typically trade securities taken from the three prominent agencies – Ginnie Mae, Fannie Mae and Freddie Mac. These agency securities usually come with high-quality ratings and are explicitly or somewhat implicitly backed by the U.S. government.
While MBS may offer modestly higher yields relative to U.S. Treasuries, the mortgage-backed bonds are exposed to prepayment risk – if rates dip before the security’s maturity, a homeowner can refinance debt, causing an investor to get back the principal early and reinvest it in a security with a lower yield.