MBBA vs. MBB

Last updated Jun 5, 2026

MBBA (iShares Mortgage-Backed Securities Active ETF) and MBB (iShares MBS Bond ETF) are both Mortgage Backed Securities funds from iShares. MBBA is actively managed, while MBB is passively managed. Their correlation of 0.88 suggests significant overlap in exposure. MBBA charges 0.25%/yr vs 0.06%/yr for MBB.

Performance

MBBA vs. MBB - Performance Comparison

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

Returns By Period

MBBA

• 1D: -0.10%
• 1M: 0.34%
• YTD: —
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

MBB

• 1D: 0.11%
• 1M: 0.25%
• YTD: 0.68%
• 6M: 1.10%
• 1Y: 6.17%
• 3Y*: 4.42%
• 5Y*: 0.36%
• 10Y*: 1.31%

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

MBBA vs. MBB - Yearly Performance Comparison

	2026 (YTD)
MBBA iShares Mortgage-Backed Securities Active ETF	0.54%
MBB iShares MBS Bond ETF	0.13%

Correlation

The correlation between MBBA and MBB is 0.88, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (All Time) Calculated using the full available price history since Jan 27, 2026	0.88

Return for Risk

MBBA vs. MBB — Risk / Return Rank

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

MBB

MBB Risk / Return Rank: 41
MBB Sharpe Ratio Rank: 40
MBB Sortino Ratio Rank: 41
MBB Omega Ratio Rank: 38
MBB Calmar Ratio Rank: 43
MBB Martin Ratio Rank: 44

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.

MBBA vs. MBB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Mortgage-Backed Securities Active ETF (MBBA) 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.

Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.

Sharpe Ratios by Period

	MBBA	MBB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	—	1.39	—
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	0.33	0.59	-0.25

Drawdowns

MBBA vs. MBB - Drawdown Comparison

The maximum MBBA drawdown since its inception was -2.83%, smaller than the maximum MBB drawdown of -17.64%. Use the drawdown chart below to compare losses from any high point for MBBA and MBB.

Drawdown Indicators

	MBBA	MBB	Difference
Max Drawdown Largest peak-to-trough decline	-2.83%	-17.64%	+14.81%
Max Drawdown (1Y) Largest decline over 1 year	—	-2.94%	—
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	-1.27%	-1.42%	+0.15%
Average Drawdown Average peak-to-trough decline	-1.12%	-2.35%	+1.23%
Ulcer Index Depth and duration of drawdowns from previous peaks	—	0.89%	—

Volatility

Volatility by Period

	MBBA	MBB	Difference
Volatility (1M) Calculated over the trailing 1-month period	—	1.58%	—
Volatility (6M) Calculated over the trailing 6-month period	—	3.23%	—
Volatility (1Y) Calculated over the trailing 1-year period	4.64%	4.51%	+0.13%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.64%	6.81%	-2.17%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.64%	5.31%	-0.67%

MBBA vs. MBB - Expense Ratio Comparison

MBBA has a 0.25% expense ratio, which is higher than MBB's 0.06% 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%.

Dividends

MBBA vs. MBB - Dividend Comparison

MBBA's dividend yield for the trailing twelve months is around 1.84%, less than MBB's 4.27% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MBB iShares MBS Bond ETF	4.27%	4.21%	3.94%	3.40%	2.31%	1.05%	2.10%	2.77%	2.64%	2.23%	2.58%	2.66%
MBBA iShares Mortgage-Backed Securities Active ETF	1.84%	0.00%	0.00%	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 MBBA and MBB in my portfolio?

MBBA and MBB have a correlation of 0.88, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which ETF is better, MBBA or MBB?

On fees, MBB is cheaper at 0.06% per year. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF is cheaper, MBBA or MBB?

MBB is cheaper with a 0.06% expense ratio, compared with 0.25% for MBBA.

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

MBB has the higher dividend yield at 4.27%, compared with 1.84% for MBBA.

What is the main difference between MBBA and MBB?

Their fees differ too: 0.25% for MBBA and 0.06% for MBB.