MBSD vs. MBB
MBSD (FlexShares Disciplined Duration MBS Index Fund) and MBB (iShares MBS Bond ETF) are both Mortgage Backed Securities funds - MBSD tracks the ICE BofA Constrained Duration US Mortgage Backed Securities while MBB tracks the Barclays Capital U.S. MBS Index. Both are passively managed. Over the past 10 years, MBSD returned 1.37%/yr vs 1.29%/yr for MBB. A 0.64 correlation means they provide meaningful diversification when combined. MBSD charges 0.20%/yr vs 0.06%/yr for MBB.
Performance
MBSD vs. MBB - Performance Comparison
Loading charts...
Returns By Period
In the year-to-date period, MBSD achieves a 0.51% return, which is significantly lower than MBB's 0.73% return. Over the past 10 years, MBSD has outperformed MBB with an annualized return of 1.37%, while MBB has yielded a comparatively lower 1.29% annualized return.
MBSD
- 1D
- -0.21%
- 1M
- 0.36%
- YTD
- 0.51%
- 6M
- 0.48%
- 1Y
- 4.60%
- 3Y*
- 4.23%
- 5Y*
- 0.71%
- 10Y*
- 1.37%
MBB
- 1D
- -0.24%
- 1M
- 0.53%
- YTD
- 0.73%
- 6M
- 0.86%
- 1Y
- 5.95%
- 3Y*
- 4.31%
- 5Y*
- 0.42%
- 10Y*
- 1.29%
MBSD vs. MBB - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
MBSD FlexShares Disciplined Duration MBS Index Fund | 0.51% | 7.12% | 2.30% | 4.46% | -9.49% | -1.40% | 5.43% | 6.05% | 0.32% | 0.86% |
MBB iShares MBS Bond ETF | 0.73% | 8.38% | 1.31% | 5.01% | -11.74% | -1.43% | 4.08% | 6.18% | 0.82% | 2.49% |
Correlation
The correlation between MBSD and MBB is 0.87, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.87 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.90 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.87 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.68 |
Correlation (All Time) Calculated using the full available price history since Sep 4, 2014 | 0.64 |
Over the past year, MBSD and MBB have become more correlated (0.87) than their long-term average of 0.64, meaning their price movements have been converging.
Compare stocks, funds, or ETFs
Search for stocks, ETFs, and funds for a quick comparison or use the comparison tool for more options.
Return for Risk
MBSD vs. MBB — Risk / Return Rank
MBSD
MBB
MBSD vs. MBB - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for FlexShares Disciplined Duration MBS Index Fund (MBSD) and iShares MBS Bond ETF (MBB). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.
Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.
| MBSD | MBB | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.02 | ||
| Sortino ratioReturn per unit of downside risk | -0.02 | ||
| Omega ratioGain probability vs. loss probability | 1.24 | 1.24 | 0.00 |
| Calmar ratioReturn relative to maximum drawdown | 2.12 | 2.03 | +0.09 |
| Martin ratioReturn relative to average drawdown | 6.39 | 6.36 | +0.02 |
Loading charts...
Drawdowns
MBSD vs. MBB - Drawdown Comparison
The maximum MBSD drawdown since its inception was -14.36%, smaller than the maximum MBB drawdown of -17.64%. Use the drawdown chart below to compare losses from any high point for MBSD and MBB.
Loading charts...
Drawdown Indicators
| MBSD | MBB | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -14.36% | -17.64% | +3.28% |
Max Drawdown (1Y)Largest decline over 1 year | -2.17% | -2.94% | +0.77% |
Max Drawdown (3Y)Largest decline over 3 years | -4.68% | -7.68% | +3.00% |
Max Drawdown (5Y)Largest decline over 5 years | -14.10% | -17.19% | +3.09% |
Max Drawdown (10Y)Largest decline over 10 years | -14.36% | -17.64% | +3.28% |
Current DrawdownCurrent decline from peak | -1.11% | -1.38% | +0.27% |
Average DrawdownAverage peak-to-trough decline | -2.81% | -2.34% | -0.47% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.72% | 0.94% | -0.22% |
Volatility
MBSD vs. MBB - Volatility Comparison
The current volatility for FlexShares Disciplined Duration MBS Index Fund (MBSD) is 0.97%, while iShares MBS Bond ETF (MBB) has a volatility of 1.27%. This indicates that MBSD experiences smaller price fluctuations and is considered to be less risky than MBB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
Loading charts...
Volatility by Period
| MBSD | MBB | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 0.97% | 1.27% | -0.30% |
Volatility (6M)Calculated over the trailing 6-month period | 2.53% | 3.33% | -0.80% |
Volatility (1Y)Calculated over the trailing 1-year period | 3.50% | 4.47% | -0.97% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 5.16% | 6.83% | -1.67% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 4.27% | 5.32% | -1.05% |
MBSD vs. MBB - Expense Ratio Comparison
MBSD has a 0.20% expense ratio, which is higher than MBB's 0.06% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.
Dividends
MBSD vs. MBB - Dividend Comparison
MBSD's dividend yield for the trailing twelve months is around 4.19%, less than MBB's 4.27% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
MBB iShares MBS Bond ETF | 4.27% | 4.21% | 3.94% | 3.40% | 2.31% | 1.05% | 2.10% | 2.77% | 2.64% | 2.23% | 2.58% | 2.66% |
MBSD FlexShares Disciplined Duration MBS Index Fund | 4.19% | 4.23% | 3.91% | 3.39% | 3.03% | 2.41% | 2.78% | 3.42% | 3.22% | 3.30% | 3.02% | 3.46% |
Frequently Asked Questions
MBSD and MBB have a correlation of 0.87, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
MBB has higher volatility (1.27%) compared to MBSD (0.97%). In terms of maximum drawdown, MBSD dropped -14.36% vs MBB's -17.64%.
On 10-year performance, MBSD leads with 1.37% vs 1.29% for MBB. On fees, MBB is cheaper at 0.06% per year. On volatility, MBSD has been the lower-risk option at 0.97%. The better choice depends on whether you care most about return, fees, risk, or income.
Over the 10-year period, MBSD has performed better with a 1.37% return vs 1.29%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.
MBB is cheaper with a 0.06% expense ratio, compared with 0.20% for MBSD.
MBB has the higher dividend yield at 4.27%, compared with 4.19% for MBSD.
MBSD tracks ICE BofA Constrained Duration US Mortgage Backed Securities, while MBB tracks Barclays Capital U.S. MBS Index. They also come from different issuers: Northern Trust and iShares. Their fees differ too: 0.20% for MBSD and 0.06% for MBB.
MBB currently has the higher Sharpe Ratio (1.34 vs 1.32), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.
Find the right allocation for MBSD and MBB
Add both to a portfolio and optimize allocations for your target — whether that's maximizing returns, minimizing drawdowns, or balancing risk across holdings.
Open Portfolio Optimizer