SMBS vs. MBB

Last updated Jun 4, 2026

SMBS (Schwab Mortgage-Backed Securities ETF) and MBB (iShares MBS Bond ETF) are both Mortgage Backed Securities funds - SMBS tracks the Bloomberg US MBS Float Adjusted Total Return Index while MBB tracks the Barclays Capital U.S. MBS Index. Both are passively managed. Over the past year, SMBS returned 6.78% vs 6.76% for MBB. Their correlation of 0.94 suggests significant overlap in exposure. SMBS charges 0.03%/yr vs 0.06%/yr for MBB.

Performance

SMBS vs. MBB - Performance Comparison

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

Returns By Period

In the year-to-date period, SMBS achieves a 0.70% return, which is significantly higher than MBB's 0.58% return.

SMBS

• 1D: -0.24%
• 1M: 0.33%
• YTD: 0.70%
• 6M: 0.82%
• 1Y: 6.78%
• 3Y*: —
• 5Y*: —
• 10Y*: —

MBB

• 1D: -0.23%
• 1M: 0.31%
• YTD: 0.58%
• 6M: 0.71%
• 1Y: 6.76%
• 3Y*: 4.36%
• 5Y*: 0.34%
• 10Y*: 1.30%

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

SMBS vs. MBB - Yearly Performance Comparison

	2026 (YTD)	2025	2024
SMBS Schwab Mortgage-Backed Securities ETF	0.70%	8.15%	-0.07%
MBB iShares MBS Bond ETF	0.58%	8.38%	-0.10%

Correlation

The correlation between SMBS and MBB is 0.94, 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	0.94
Correlation (All Time) Calculated using the full available price history since Nov 20, 2024	0.94

The correlation between SMBS and MBB has been stable across timeframes, ranging from 0.94 to 0.94 - a consistent structural relationship.

Return for Risk

SMBS vs. MBB — Risk / Return Rank

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

SMBS

SMBS Risk / Return Rank: 48
SMBS Sharpe Ratio Rank: 47
SMBS Sortino Ratio Rank: 49
SMBS Omega Ratio Rank: 47
SMBS Calmar Ratio Rank: 49
SMBS Martin Ratio Rank: 49

MBB

MBB Risk / Return Rank: 44
MBB Sharpe Ratio Rank: 42
MBB Sortino Ratio Rank: 43
MBB Omega Ratio Rank: 41
MBB Calmar Ratio Rank: 46
MBB Martin Ratio Rank: 46

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.

SMBS vs. MBB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Schwab Mortgage-Backed Securities ETF (SMBS) 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.

	SMBS	MBB	Difference
Sharpe ratio Return per unit of total volatility	1.64	1.51	+0.14
Sortino ratio Return per unit of downside risk	2.42	2.22	+0.20
Omega ratio Gain probability vs. loss probability	1.30	1.27	+0.03
Calmar ratio Return relative to maximum drawdown	2.41	2.31	+0.10
Martin ratio Return relative to average drawdown	8.21	7.64	+0.57
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

SMBS vs. MBB - Sharpe Ratio Comparison

The current SMBS Sharpe Ratio is 1.64, which is comparable to the MBB Sharpe Ratio of 1.51. The chart below compares the historical Sharpe Ratios of SMBS and MBB, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	SMBS	MBB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.64	1.51	+0.14
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.05	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.25	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.18	0.58	+0.60

Drawdowns

SMBS vs. MBB - Drawdown Comparison

The maximum SMBS drawdown since its inception was -3.20%, smaller than the maximum MBB drawdown of -17.64%. Use the drawdown chart below to compare losses from any high point for SMBS and MBB.

Drawdown Indicators

	SMBS	MBB	Difference
Max Drawdown Largest peak-to-trough decline	-3.20%	-17.64%	+14.44%
Max Drawdown (1Y) Largest decline over 1 year	-2.83%	-2.94%	+0.11%
Max Drawdown (3Y) Largest decline over 3 years	—	-7.68%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-17.19%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-17.64%	—
Current Drawdown Current decline from peak	-1.33%	-1.52%	+0.19%
Average Drawdown Average peak-to-trough decline	-0.84%	-2.35%	+1.51%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.83%	0.89%	-0.06%

Volatility

SMBS vs. MBB - Volatility Comparison

Schwab Mortgage-Backed Securities ETF (SMBS) and iShares MBS Bond ETF (MBB) have volatilities of 1.55% and 1.59%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SMBS	MBB	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.55%	1.59%	-0.04%
Volatility (6M) Calculated over the trailing 6-month period	3.03%	3.23%	-0.20%
Volatility (1Y) Calculated over the trailing 1-year period	4.15%	4.51%	-0.36%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.86%	6.81%	-1.95%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.86%	5.31%	-0.45%

SMBS vs. MBB - Expense Ratio Comparison

SMBS has a 0.03% expense ratio, which is lower than MBB's 0.06% 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

SMBS vs. MBB - Dividend Comparison

SMBS's dividend yield for the trailing twelve months is around 5.17%, more than MBB's 4.28% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MBB iShares MBS Bond ETF	4.28%	4.21%	3.94%	3.40%	2.31%	1.05%	2.10%	2.77%	2.64%	2.23%	2.58%	2.66%
SMBS Schwab Mortgage-Backed Securities ETF	5.17%	4.83%	0.50%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both SMBS and MBB in my portfolio?

With a correlation of 0.94, SMBS and MBB move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, SMBS or MBB?

MBB has higher volatility (1.59%) compared to SMBS (1.55%). In terms of maximum drawdown, SMBS dropped -3.20% vs MBB's -17.64%.

Which ETF is better, SMBS or MBB?

On 1-year performance, SMBS leads with 6.78% vs 6.76% for MBB. On fees, SMBS is cheaper at 0.03% per year. Their volatility is very similar. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, SMBS or MBB?

Over the 1-year period, SMBS has performed better with a 6.78% return vs 6.76%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, SMBS or MBB?

SMBS is cheaper with a 0.03% expense ratio, compared with 0.06% for MBB.

Which ETF pays a higher dividend yield, SMBS or MBB?

SMBS has the higher dividend yield at 5.17%, compared with 4.28% for MBB.

What is the main difference between SMBS and MBB?

SMBS tracks Bloomberg US MBS Float Adjusted Total Return Index, while MBB tracks Barclays Capital U.S. MBS Index. They also come from different issuers: Charles Schwab and iShares. Their fees differ too: 0.03% for SMBS and 0.06% for MBB.

Which has better risk-adjusted returns?

SMBS currently has the higher Sharpe Ratio (1.64 vs 1.51), 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.