MBB — iShares MBS ETF

Overview

The iShares MBS ETF, identified by the ticker MBB, operates within the Mortgage-Backed category and is managed by the issuer iShares. With assets under management totaling $39.6 billion and a current share price of $93.69, the fund demonstrates significant investor adoption relative to its peers. It holds an overall rank of #81 out of 120 tracked ETFs across all categories and has received an ETFValuer grade of C with a score of 57.4 out of 100. The fund offers a low-cost structure with an expense ratio of 0.04% while providing a dividend yield of 4.26%. This combination of substantial assets and a high yield suggests a focus on income generation within a category containing only two other tracked ETFs. The fund's pricing and asset size position it as a major vehicle for exposure to mortgage-backed securities despite its mid-tier ranking.

Over the one-day period, the fund declined by 0.16%, following a broader weekly drop of 0.52%. Short-term momentum shifted slightly positive over the last month with a gain of 0.30%, though the three-month return reversed to a loss of 0.53%. The six-month performance remained flat at 0.00%, while year-to-date returns have edged up to +0.22%. A more distinct positive trend emerges over longer horizons, with the one-year return reaching +4.99% and the three-year return accumulating to +12.31%. This trajectory indicates a divergence where recent short-term fluctuations have been muted compared to the sustained growth observed over the past three years.

The fund carries a volatility label of Very Low, yet it exhibits a beta of 1.14, indicating it moves slightly more than the broader market despite its classification. A Sharpe ratio of -0.00 suggests that the risk-adjusted returns have been negligible relative to the risk taken over the measured period. The maximum drawdown recorded is -7.68%, which quantifies the peak-to-trough decline experienced by investors. This combination of a low volatility label with a beta above 1.0 and a negative Sharpe ratio implies that while the fund may not experience extreme daily swings, its returns have not adequately compensated for its market sensitivity. The -7.68% drawdown further illustrates the potential for significant temporary losses even within a category generally perceived as stable.

AI-generated summary based on the data on this page.

MBB Top Holdings

Holdings as of 2026-02-28 per the fund's most recent SEC N-PORT-P filing.

Market Backdrop

10-Year Treasury Yield: 4.55% (as of 2026-07-07) — The yield on 10-year US Treasury bonds — the standard "risk-free rate" benchmark used to contextualize this fund’s Sharpe ratio and returns.

CBOE Volatility Index (VIX): 16.13 (as of 2026-07-07) — A real-time gauge of expected S&P 500 volatility over the next 30 days — useful context for this fund’s own volatility label.

Federal Funds Rate: 3.63% (as of 2026-06-01) — The Federal Reserve’s target policy rate, which anchors short-term borrowing costs across the economy.

MBB Performance History

How MBB Compares to Other Mortgage-Backed ETFs