MBB vs. IWM
Compare and contrast key facts about iShares MBS Bond ETF (MBB) and iShares Russell 2000 ETF (IWM).
MBB and IWM are both exchange-traded funds (ETFs), meaning they are traded on stock exchanges and can be bought and sold throughout the day. MBB is a passively managed fund by iShares that tracks the performance of the Barclays Capital U.S. MBS Index. It was launched on Mar 16, 2007. IWM is a passively managed fund by iShares that tracks the performance of the Russell 2000 Index. It was launched on May 22, 2000. Both MBB and IWM are passive ETFs, meaning that they are not actively managed but aim to replicate the performance of the underlying index as closely as possible.
Performance
MBB vs. IWM - Performance Comparison
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MBB vs. IWM - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
MBB iShares MBS Bond ETF | 0.41% | 8.38% | 1.31% | 5.01% | -11.74% | -1.43% | 4.08% | 6.18% | 0.82% | 2.49% |
IWM iShares Russell 2000 ETF | 0.93% | 12.66% | 11.38% | 16.83% | -20.48% | 14.54% | 20.03% | 25.39% | -11.12% | 14.58% |
Returns By Period
In the year-to-date period, MBB achieves a 0.41% return, which is significantly lower than IWM's 0.93% return. Over the past 10 years, MBB has underperformed IWM with an annualized return of 1.34%, while IWM has yielded a comparatively higher 9.76% annualized return.
MBB
- 1D
- 0.24%
- 1M
- -1.69%
- YTD
- 0.41%
- 6M
- 1.92%
- 1Y
- 5.63%
- 3Y*
- 4.09%
- 5Y*
- 0.40%
- 10Y*
- 1.34%
IWM
- 1D
- 3.50%
- 1M
- -4.96%
- YTD
- 0.93%
- 6M
- 3.02%
- 1Y
- 25.66%
- 3Y*
- 12.94%
- 5Y*
- 3.34%
- 10Y*
- 9.76%
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MBB vs. IWM - Expense Ratio Comparison
MBB has a 0.06% expense ratio, which is lower than IWM's 0.19% 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%.
Return for Risk
MBB vs. IWM — Risk / Return Rank
MBB
IWM
MBB vs. IWM - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares MBS Bond ETF (MBB) and iShares Russell 2000 ETF (IWM). 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.
| MBB | IWM | Difference | |
|---|---|---|---|
Sharpe ratioReturn per unit of total volatility | 1.14 | 1.11 | +0.03 |
Sortino ratioReturn per unit of downside risk | 1.63 | 1.66 | -0.03 |
Omega ratioGain probability vs. loss probability | 1.20 | 1.21 | -0.01 |
Calmar ratioReturn relative to maximum drawdown | 2.18 | 1.82 | +0.36 |
Martin ratioReturn relative to average drawdown | 6.00 | 6.76 | -0.76 |
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month. | |||
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Sharpe Ratios by Period
| MBB | IWM | Difference | |
|---|---|---|---|
Sharpe Ratio (1Y)Calculated over the trailing 1-year period | 1.14 | 1.11 | +0.03 |
Sharpe Ratio (5Y)Calculated over the trailing 5-year period | 0.06 | 0.15 | -0.09 |
Sharpe Ratio (10Y)Calculated over the trailing 10-year period | 0.25 | 0.43 | -0.17 |
Sharpe Ratio (All Time)Calculated using the full available price history | 0.59 | 0.34 | +0.25 |
Correlation
The correlation between MBB and IWM is -0.08. This indicates that the assets' prices tend to move in opposite directions. Negative correlation can be particularly beneficial for diversification and risk management, as one asset may offset the losses of the other during market fluctuations.
Dividends
MBB vs. IWM - Dividend Comparison
MBB's dividend yield for the trailing twelve months is around 4.22%, more than IWM's 1.02% yield.
| TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
MBB iShares MBS Bond ETF | 4.22% | 4.21% | 3.94% | 3.40% | 2.31% | 1.05% | 2.10% | 2.77% | 2.64% | 2.23% | 2.58% | 2.66% |
IWM iShares Russell 2000 ETF | 1.02% | 1.04% | 1.15% | 1.35% | 1.48% | 0.94% | 1.04% | 1.26% | 1.40% | 1.26% | 1.38% | 1.54% |
Drawdowns
MBB vs. IWM - Drawdown Comparison
The maximum MBB drawdown since its inception was -17.64%, smaller than the maximum IWM drawdown of -59.05%. Use the drawdown chart below to compare losses from any high point for MBB and IWM.
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Drawdown Indicators
| MBB | IWM | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -17.64% | -59.05% | +41.41% |
Max Drawdown (1Y)Largest decline over 1 year | -2.64% | -13.74% | +11.10% |
Max Drawdown (5Y)Largest decline over 5 years | -17.19% | -31.91% | +14.72% |
Max Drawdown (10Y)Largest decline over 10 years | -17.64% | -41.13% | +23.49% |
Current DrawdownCurrent decline from peak | -1.69% | -7.91% | +6.22% |
Average DrawdownAverage peak-to-trough decline | -2.36% | -10.83% | +8.47% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.96% | 3.70% | -2.74% |
Volatility
MBB vs. IWM - Volatility Comparison
The current volatility for iShares MBS Bond ETF (MBB) is 1.98%, while iShares Russell 2000 ETF (IWM) has a volatility of 7.47%. This indicates that MBB experiences smaller price fluctuations and is considered to be less risky than IWM based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| MBB | IWM | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.98% | 7.47% | -5.49% |
Volatility (6M)Calculated over the trailing 6-month period | 3.00% | 14.47% | -11.47% |
Volatility (1Y)Calculated over the trailing 1-year period | 4.97% | 23.18% | -18.21% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.77% | 22.55% | -15.78% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.27% | 22.99% | -17.72% |