SPMB vs. MBSD
SPMB (SPDR Portfolio Mortgage Backed Bond ETF) and MBSD (FlexShares Disciplined Duration MBS Index Fund) are both Mortgage Backed Securities funds - SPMB tracks the Bloomberg US Aggregate Securitized - MBS while MBSD tracks the ICE BofA Constrained Duration US Mortgage Backed Securities. Both are passively managed. Over the past 10 years, SPMB returned 1.28%/yr vs 1.37%/yr for MBSD. A 0.59 correlation means they provide meaningful diversification when combined. SPMB charges 0.04%/yr vs 0.20%/yr for MBSD.
Performance
SPMB vs. MBSD - Performance Comparison
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Returns By Period
In the year-to-date period, SPMB achieves a 0.76% return, which is significantly higher than MBSD's 0.51% return. Over the past 10 years, SPMB has underperformed MBSD with an annualized return of 1.28%, while MBSD has yielded a comparatively higher 1.37% annualized return.
SPMB
- 1D
- -0.25%
- 1M
- 0.65%
- YTD
- 0.76%
- 6M
- 0.83%
- 1Y
- 5.97%
- 3Y*
- 4.27%
- 5Y*
- 0.40%
- 10Y*
- 1.28%
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%
SPMB vs. MBSD - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
SPMB SPDR Portfolio Mortgage Backed Bond ETF | 0.76% | 8.29% | 1.35% | 5.09% | -12.05% | -1.46% | 4.19% | 6.16% | 1.01% | 2.13% |
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% |
Correlation
The correlation between SPMB and MBSD is 0.86, 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 | 0.86 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.89 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.86 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.65 |
Correlation (All Time) Calculated using the full available price history since Sep 4, 2014 | 0.59 |
Over the past year, SPMB and MBSD have become more correlated (0.86) than their long-term average of 0.59, meaning their price movements have been converging.
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Return for Risk
SPMB vs. MBSD — Risk / Return Rank
SPMB
MBSD
SPMB vs. MBSD - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for SPDR Portfolio Mortgage Backed Bond ETF (SPMB) and FlexShares Disciplined Duration MBS Index Fund (MBSD). 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.
| SPMB | MBSD | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | +0.10 | ||
| Sortino ratioReturn per unit of downside risk | +0.19 | ||
| Omega ratioGain probability vs. loss probability | 1.26 | 1.24 | +0.02 |
| Calmar ratioReturn relative to maximum drawdown | 2.08 | 2.12 | -0.05 |
| Martin ratioReturn relative to average drawdown | 6.45 | 6.39 | +0.07 |
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Drawdowns
SPMB vs. MBSD - Drawdown Comparison
The maximum SPMB drawdown since its inception was -18.03%, which is greater than MBSD's maximum drawdown of -14.36%. Use the drawdown chart below to compare losses from any high point for SPMB and MBSD.
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Drawdown Indicators
| SPMB | MBSD | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -18.03% | -14.36% | -3.67% |
Max Drawdown (1Y)Largest decline over 1 year | -2.89% | -2.17% | -0.72% |
Max Drawdown (3Y)Largest decline over 3 years | -7.66% | -4.68% | -2.98% |
Max Drawdown (5Y)Largest decline over 5 years | -17.49% | -14.10% | -3.39% |
Max Drawdown (10Y)Largest decline over 10 years | -18.03% | -14.36% | -3.67% |
Current DrawdownCurrent decline from peak | -1.34% | -1.11% | -0.23% |
Average DrawdownAverage peak-to-trough decline | -2.85% | -2.81% | -0.04% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.93% | 0.72% | +0.21% |
Volatility
SPMB vs. MBSD - Volatility Comparison
SPDR Portfolio Mortgage Backed Bond ETF (SPMB) has a higher volatility of 1.23% compared to FlexShares Disciplined Duration MBS Index Fund (MBSD) at 0.97%. This indicates that SPMB's price experiences larger fluctuations and is considered to be riskier than MBSD based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| SPMB | MBSD | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.23% | 0.97% | +0.26% |
Volatility (6M)Calculated over the trailing 6-month period | 3.19% | 2.53% | +0.66% |
Volatility (1Y)Calculated over the trailing 1-year period | 4.23% | 3.50% | +0.73% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.79% | 5.16% | +1.63% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 7.61% | 4.27% | +3.34% |
SPMB vs. MBSD - Expense Ratio Comparison
SPMB has a 0.04% expense ratio, which is lower than MBSD's 0.20% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.
Dividends
SPMB vs. MBSD - Dividend Comparison
SPMB's dividend yield for the trailing twelve months is around 4.08%, less than MBSD's 4.19% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
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% |
SPMB SPDR Portfolio Mortgage Backed Bond ETF | 4.08% | 3.98% | 3.76% | 3.21% | 2.98% | 2.59% | 2.95% | 3.24% | 3.36% | 3.13% | 2.99% | 3.05% |
Frequently Asked Questions
SPMB and MBSD have a correlation of 0.86, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
SPMB has higher volatility (1.23%) compared to MBSD (0.97%). In terms of maximum drawdown, SPMB dropped -18.03% vs MBSD's -14.36%.
On 10-year performance, MBSD leads with 1.37% vs 1.28% for SPMB. On fees, SPMB is cheaper at 0.04% 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 1.28%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.
SPMB is cheaper with a 0.04% expense ratio, compared with 0.20% for MBSD.
MBSD has the higher dividend yield at 4.19%, compared with 4.08% for SPMB.
SPMB tracks Bloomberg US Aggregate Securitized - MBS, while MBSD tracks ICE BofA Constrained Duration US Mortgage Backed Securities. They also come from different issuers: State Street and Northern Trust. Their fees differ too: 0.04% for SPMB and 0.20% for MBSD.
SPMB currently has the higher Sharpe Ratio (1.42 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.
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