MBB vs. SPMB

Last updated Apr 1, 2026

Compare and contrast key facts about iShares MBS Bond ETF (MBB) and SPDR Portfolio Mortgage Backed Bond ETF (SPMB).

MBB and SPMB 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. SPMB is a passively managed fund by State Street that tracks the performance of the Bloomberg US Aggregate Securitized - MBS. It was launched on Jan 15, 2009. Both MBB and SPMB 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. SPMB - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares MBS Bond ETF (MBB) and SPDR Portfolio Mortgage Backed Bond ETF (SPMB). The values are adjusted to include any dividend payments, if applicable.

MBB vs. SPMB - 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%
SPMB SPDR Portfolio Mortgage Backed Bond ETF	0.51%	8.29%	1.35%	5.09%	-12.05%	-1.46%	4.19%	6.16%	1.01%	2.13%

Returns By Period

In the year-to-date period, MBB achieves a 0.41% return, which is significantly lower than SPMB's 0.51% return. Both investments have delivered pretty close results over the past 10 years, with MBB having a 1.34% annualized return and SPMB not far behind at 1.29%.

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%

SPMB

• 1D: 0.31%
• 1M: -1.58%
• YTD: 0.51%
• 6M: 1.98%
• 1Y: 5.73%
• 3Y*: 4.11%
• 5Y*: 0.37%
• 10Y*: 1.29%

*Multi-year figures are annualized to reflect compound growth (CAGR)

MBB vs. SPMB - Expense Ratio Comparison

MBB has a 0.06% expense ratio, which is higher than SPMB's 0.04% 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%.

MBB

iShares MBS Bond ETF

SPMB

SPDR Portfolio Mortgage Backed Bond ETF

Return for Risk

MBB vs. SPMB — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

MBB

MBB Risk / Return Rank: 67
MBB Sharpe Ratio Rank: 67
MBB Sortino Ratio Rank: 67
MBB Omega Ratio Rank: 57
MBB Calmar Ratio Rank: 81
MBB Martin Ratio Rank: 63

SPMB

SPMB Risk / Return Rank: 66
SPMB Sharpe Ratio Rank: 68
SPMB Sortino Ratio Rank: 68
SPMB Omega Ratio Rank: 59
SPMB Calmar Ratio Rank: 77
SPMB Martin Ratio Rank: 60

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

MBB vs. SPMB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares MBS Bond ETF (MBB) and SPDR Portfolio Mortgage Backed Bond ETF (SPMB). 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	SPMB	Difference
Sharpe ratio Return per unit of total volatility	1.14	1.18	-0.04
Sortino ratio Return per unit of downside risk	1.63	1.69	-0.06
Omega ratio Gain probability vs. loss probability	1.20	1.21	-0.01
Calmar ratio Return relative to maximum drawdown	2.18	2.01	+0.18
Martin ratio Return relative to average drawdown	6.00	5.76	+0.25
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MBB vs. SPMB - Sharpe Ratio Comparison

The current MBB Sharpe Ratio is 1.14, which is comparable to the SPMB Sharpe Ratio of 1.18. The chart below compares the historical Sharpe Ratios of MBB and SPMB, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	MBB	SPMB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.14	1.18	-0.04
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.06	0.05	0.00
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.25	0.17	+0.08
Sharpe Ratio (All Time) Calculated using the full available price history	0.59	0.34	+0.25

Correlation

The correlation between MBB and SPMB is 0.71, which is considered to be high. That indicates a strong positive relationship between their price movements. Having highly-correlated positions in a portfolio may signal a lack of diversification, potentially leading to increased risk during market downturns.

Dividends

MBB vs. SPMB - Dividend Comparison

MBB's dividend yield for the trailing twelve months is around 4.22%, more than SPMB's 4.02% 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%
SPMB SPDR Portfolio Mortgage Backed Bond ETF	4.02%	3.98%	3.76%	3.21%	2.98%	2.59%	2.95%	3.24%	3.36%	3.13%	2.99%	3.05%

Drawdowns

MBB vs. SPMB - Drawdown Comparison

The maximum MBB drawdown since its inception was -17.64%, roughly equal to the maximum SPMB drawdown of -18.03%. Use the drawdown chart below to compare losses from any high point for MBB and SPMB.

Drawdown Indicators

	MBB	SPMB	Difference
Max Drawdown Largest peak-to-trough decline	-17.64%	-18.03%	+0.39%
Max Drawdown (1Y) Largest decline over 1 year	-2.64%	-2.93%	+0.29%
Max Drawdown (5Y) Largest decline over 5 years	-17.19%	-17.49%	+0.30%
Max Drawdown (10Y) Largest decline over 10 years	-17.64%	-18.03%	+0.39%
Current Drawdown Current decline from peak	-1.69%	-1.58%	-0.11%
Average Drawdown Average peak-to-trough decline	-2.36%	-2.87%	+0.51%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.96%	1.02%	-0.06%

Volatility

MBB vs. SPMB - Volatility Comparison

iShares MBS Bond ETF (MBB) has a higher volatility of 1.98% compared to SPDR Portfolio Mortgage Backed Bond ETF (SPMB) at 1.83%. This indicates that MBB's price experiences larger fluctuations and is considered to be riskier than SPMB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MBB	SPMB	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.98%	1.83%	+0.15%
Volatility (6M) Calculated over the trailing 6-month period	3.00%	2.77%	+0.23%
Volatility (1Y) Calculated over the trailing 1-year period	4.97%	4.88%	+0.09%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.77%	6.73%	+0.04%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.27%	7.59%	-2.32%