Understanding the iShares MBS ETF (MBB)

What this ETF is trying to do

The iShares MBS ETF, known by its ticker symbol MBB, is an exchange-traded fund. This type of investment is designed to track a specific group of assets. In this case, it focuses on Mortgage-Backed Securities (MBS).

What the numbers show

As of July 10, 2026, the current price of one share is $93.72. Looking at how the price has moved over time, we can see different results. The price one year ago was estimated to be around $93.24.

If you look at the "total return," which includes both price changes and the money paid out to investors, the one-year total return was 4.8765%. However, if you only look at the "price return" (just the change in the share price), it was much lower at 0.5148%. This shows that a big part of the value came from the payments made to investors rather than the price going up.

Income and distribution explanation

Some investors look for ETFs that pay them regular money, which is called a "distribution." This ETF has a distribution yield of 4.3001%. Over the last 12 months, it made 12 payments. These payments usually happen once every month. The total amount of distributions paid out over the last year was $4.0301 per share.

It is important to remember that a high yield alone can be misleading. A high percentage might look good, 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 ETF drops, causing the share price to fall over time. If an ETF's price collapses, it can destroy your "principal," which is the original money you put in.

For example, if you invested $10,000 into an ETF and the share price dropped significantly, you might end up with much less than $10,000, even if the ETF pays you monthly income. This is why income investors usually prefer ETFs that go "sideways" (stay at a similar price) or move slightly up. They want their original money to stay safe while they collect the payments.

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

Pros

• The ETF provides regular monthly income.

• The price has remained relatively stable over the last year.

• The total return over three years was 15.1723%.

Cons

• The price itself (price return) does not grow very quickly on its own.

• Year-to-date, the price return is negative at -1.5753%.

Beginner takeaway

When looking at an ETF like MBB, it is helpful to look at both the price and the total return. While the share price might not move up a lot, the monthly distributions add value over time. Always check if the price is staying stable so that your original investment stays protected.