SPAB vs. CMBS
SPAB (SPDR Portfolio Aggregate Bond ETF) and CMBS (iShares CMBS ETF) are both exchange-traded funds - SPAB is a Total Bond Market fund tracking the Bloomberg U.S. Aggregate Bond Index, while CMBS is a Mortgage Backed Securities fund tracking the Barclays Capital U.S. CMBS (ERISA Only) Index. Both are passively managed. Over the past 10 years, SPAB returned 1.50%/yr vs 2.02%/yr for CMBS. A 0.52 correlation means they provide meaningful diversification when combined. SPAB charges 0.03%/yr vs 0.25%/yr for CMBS.
Performance
SPAB vs. CMBS - Performance Comparison
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Returns By Period
In the year-to-date period, SPAB achieves a 0.41% return, which is significantly higher than CMBS's 0.26% return. Over the past 10 years, SPAB has underperformed CMBS with an annualized return of 1.50%, while CMBS has yielded a comparatively higher 2.02% annualized return.
SPAB
- 1D
- -0.27%
- 1M
- 0.58%
- YTD
- 0.41%
- 6M
- 0.45%
- 1Y
- 4.54%
- 3Y*
- 3.95%
- 5Y*
- 0.04%
- 10Y*
- 1.50%
CMBS
- 1D
- -0.17%
- 1M
- 0.31%
- YTD
- 0.26%
- 6M
- 0.38%
- 1Y
- 4.05%
- 3Y*
- 5.27%
- 5Y*
- 0.75%
- 10Y*
- 2.02%
SPAB vs. CMBS - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
SPAB SPDR Portfolio Aggregate Bond ETF | 0.41% | 7.25% | 1.25% | 5.56% | -13.04% | -1.77% | 7.39% | 8.67% | -0.18% | 3.71% |
CMBS iShares CMBS ETF | 0.26% | 7.67% | 4.27% | 5.06% | -11.21% | -1.82% | 7.86% | 7.94% | 0.77% | 2.95% |
Correlation
The correlation between SPAB and CMBS is 0.43, which is low. Their price movements are largely independent, making them effective diversification partners.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.43 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.57 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.66 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.58 |
Correlation (All Time) Calculated using the full available price history since Feb 16, 2012 | 0.52 |
The correlation between SPAB and CMBS shifts across timeframes, from 0.43 (1 year) to 0.66 (5 years), reflecting how their relationship changes across market environments.
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Return for Risk
SPAB vs. CMBS — Risk / Return Rank
SPAB
CMBS
SPAB vs. CMBS - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for SPDR Portfolio Aggregate Bond ETF (SPAB) and iShares CMBS ETF (CMBS). 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.
| SPAB | CMBS | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | +0.12 | ||
| Sortino ratioReturn per unit of downside risk | +0.14 | ||
| Omega ratioGain probability vs. loss probability | 1.22 | 1.19 | +0.02 |
| Calmar ratioReturn relative to maximum drawdown | 1.66 | 1.67 | -0.01 |
| Martin ratioReturn relative to average drawdown | 4.66 | 4.35 | +0.31 |
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Drawdowns
SPAB vs. CMBS - Drawdown Comparison
The maximum SPAB drawdown since its inception was -18.56%, which is greater than CMBS's maximum drawdown of -15.87%. Use the drawdown chart below to compare losses from any high point for SPAB and CMBS.
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Drawdown Indicators
| SPAB | CMBS | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -18.56% | -15.87% | -2.69% |
Max Drawdown (1Y)Largest decline over 1 year | -2.74% | -2.44% | -0.30% |
Max Drawdown (3Y)Largest decline over 3 years | -6.08% | -3.29% | -2.79% |
Max Drawdown (5Y)Largest decline over 5 years | -17.96% | -15.87% | -2.09% |
Max Drawdown (10Y)Largest decline over 10 years | -18.56% | -15.87% | -2.69% |
Current DrawdownCurrent decline from peak | -2.15% | -1.65% | -0.50% |
Average DrawdownAverage peak-to-trough decline | -3.08% | -2.95% | -0.13% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.97% | 0.93% | +0.04% |
Volatility
SPAB vs. CMBS - Volatility Comparison
The current volatility for SPDR Portfolio Aggregate Bond ETF (SPAB) is 1.09%, while iShares CMBS ETF (CMBS) has a volatility of 1.25%. This indicates that SPAB experiences smaller price fluctuations and is considered to be less risky than CMBS based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| SPAB | CMBS | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.09% | 1.25% | -0.16% |
Volatility (6M)Calculated over the trailing 6-month period | 2.69% | 2.85% | -0.16% |
Volatility (1Y)Calculated over the trailing 1-year period | 3.73% | 3.69% | +0.04% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 5.93% | 5.32% | +0.61% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.55% | 5.77% | -0.22% |
SPAB vs. CMBS - Expense Ratio Comparison
SPAB has a 0.03% expense ratio, which is lower than CMBS's 0.25% 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
SPAB vs. CMBS - Dividend Comparison
SPAB's dividend yield for the trailing twelve months is around 4.05%, more than CMBS's 3.58% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
CMBS iShares CMBS ETF | 3.58% | 3.45% | 3.31% | 2.97% | 2.65% | 2.46% | 2.83% | 2.74% | 2.70% | 2.50% | 2.29% | 2.31% |
SPAB SPDR Portfolio Aggregate Bond ETF | 4.05% | 3.97% | 3.86% | 3.34% | 2.59% | 2.11% | 2.43% | 2.92% | 2.96% | 2.67% | 2.63% | 2.59% |
Frequently Asked Questions
SPAB and CMBS have a correlation of 0.43, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
CMBS has higher volatility (1.25%) compared to SPAB (1.09%). In terms of maximum drawdown, SPAB dropped -18.56% vs CMBS's -15.87%.
On 10-year performance, CMBS leads with 2.02% vs 1.50% for SPAB. On fees, SPAB is cheaper at 0.03% per year. On volatility, SPAB has been the lower-risk option at 1.09%. The better choice depends on whether you care most about return, fees, risk, or income.
Over the 10-year period, CMBS has performed better with a 2.02% return vs 1.50%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.
SPAB is cheaper with a 0.03% expense ratio, compared with 0.25% for CMBS.
SPAB has the higher dividend yield at 4.05%, compared with 3.58% for CMBS.
SPAB is categorized as Total Bond Market, while CMBS is Mortgage Backed Securities. SPAB tracks Bloomberg U.S. Aggregate Bond Index, while CMBS tracks Barclays Capital U.S. CMBS (ERISA Only) Index. They also come from different issuers: State Street and iShares. Their fees differ too: 0.03% for SPAB and 0.25% for CMBS.
SPAB currently has the higher Sharpe Ratio (1.22 vs 1.11), 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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