Understanding the Vanguard Mortgage-Backed Securities Index Fund ETF (VMBS)

What this ETF is trying to do

The VMBS ETF is a type of fund that focuses on mortgage-backed securities. Instead of buying individual stocks in companies like Apple or Disney, this fund invests in bundles of mortgages. This helps investors gain exposure to the mortgage market through a single investment.

What the numbers show

As of July 13, 2026, the current price of one share is $46.24. Looking back at the last year, the price has changed very little, moving from an estimated $45.88 to its current price. This represents a one-year price return of about 0.78%.

However, when you look at "total return," which includes the money paid out to investors, the numbers look different. The one-year total return is 5.06%, and the three-year total return is 12.89%. This shows that much of the value comes from the payments made to shareholders rather than just the price of the share going up.

Income and distribution explanation

This ETF is designed to provide regular income. Over the last 12 months, it made 12 distributions, which means it usually pays out money every month. The "distribution yield" is 4.22%, and the total amount paid out over the last year was $1.95 per share.

It is important to remember that a high yield alone can be misleading. A high percentage might look attractive, but you must also look at whether the share price is staying steady or falling.

NAV erosion explanation

"NAV erosion" happens when the value of the underlying assets in the fund drops, causing the share price to fall over time. If an ETF's price collapses from a high number to a much lower number, it can destroy your "principal." Principal is the original money you put in. Even if the fund pays you high income, if the share price drops faster than the payments arrive, you could end up with less money than you started with.

In this case, VMBS has an erosion score of 94, which is labeled as "Stable / sideways." This means it does not show signs of severe erosion.

Pros

• It provides regular monthly income.

• The fund has shown a stable price history (sideways movement) rather than a collapsing price.

• The three-year total return shows steady growth when including distributions.

Cons

• The actual price of the share does not grow very quickly on its own.

• The year-to-date price return is currently negative at -1.78%.

Beginner takeaway

Income investors usually prefer ETFs that go "sideways" (stay at a steady price) or move slightly up. They prefer this because it means their original investment stays safe while they collect the monthly payments. Because VMBS is labeled as stable, it avoids the danger of losing significant principal through rapid price drops. Always remember to look at both the yield and the price movement together.