MBB vs. ASEC
MBB (iShares MBS Bond ETF) and ASEC (American Century Securitized Credit ETF) are both Mortgage Backed Securities funds. MBB is passively managed, while ASEC is actively managed. At a 0.20 correlation, their price movements are largely independent. MBB charges 0.06%/yr vs 0.29%/yr for ASEC.
Performance
MBB vs. ASEC - Performance Comparison
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Returns By Period
MBB
- 1D
- -0.49%
- 1M
- -0.83%
- 6M
- -0.43%
- YTD
- 0.02%
- 1Y
- 4.79%
- 3Y*
- 4.12%
- 5Y*
- 0.21%
- 10Y*
- 1.19%
ASEC
- 1D
- -0.04%
- 1M
- 0.09%
- 6M
- —
- YTD
- —
- 1Y
- —
- 3Y*
- —
- 5Y*
- —
- 10Y*
- —
MBB vs. ASEC - Yearly Performance Comparison
| 2026 (YTD) | |
|---|---|
MBB iShares MBS Bond ETF | -0.48% |
ASEC American Century Securitized Credit ETF | -0.09% |
Correlation
The correlation between MBB and ASEC is 0.20, which is low. Their price movements are largely independent, making them effective diversification partners.
| Correlation | |
|---|---|
Correlation (All Time) Calculated using the full available price history since May 28, 2026 | 0.20 |
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Return for Risk
MBB vs. ASEC — Risk / Return Rank
MBB
ASEC
Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.
MBB vs. ASEC - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares MBS Bond ETF (MBB) and American Century Securitized Credit ETF (ASEC). 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.
| MBB | ASEC | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | — | — | |
| Sortino ratioReturn per unit of downside risk | — | — | |
| Omega ratioGain probability vs. loss probability | 1.19 | — | — |
| Calmar ratioReturn relative to maximum drawdown | 1.63 | — | — |
| Martin ratioReturn relative to average drawdown | 4.97 | — | — |
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Drawdowns
MBB vs. ASEC - Drawdown Comparison
The maximum MBB drawdown since its inception was -17.64%, which is greater than ASEC's maximum drawdown of -0.46%. Use the drawdown chart below to compare losses from any high point for MBB and ASEC.
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Drawdown Indicators
| MBB | ASEC | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -17.64% | -0.46% | -17.18% |
Max Drawdown (1Y)Largest decline over 1 year | -2.94% | — | — |
Max Drawdown (3Y)Largest decline over 3 years | -7.59% | — | — |
Max Drawdown (5Y)Largest decline over 5 years | -17.19% | — | — |
Max Drawdown (10Y)Largest decline over 10 years | -17.64% | — | — |
Current DrawdownCurrent decline from peak | -2.06% | -0.19% | -1.87% |
Average DrawdownAverage peak-to-trough decline | -2.34% | -0.19% | -2.15% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.97% | — | — |
Volatility
MBB vs. ASEC - Volatility Comparison
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Volatility by Period
| MBB | ASEC | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.44% | — | — |
Volatility (6M)Calculated over the trailing 6-month period | 3.44% | — | — |
Volatility (1Y)Calculated over the trailing 1-year period | 4.43% | 1.44% | +2.99% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.84% | 1.44% | +5.40% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.33% | 1.44% | +3.89% |
MBB vs. ASEC - Expense Ratio Comparison
MBB has a 0.06% expense ratio, which is lower than ASEC's 0.29% expense ratio.
Dividends
MBB vs. ASEC - Dividend Comparison
MBB's dividend yield for the trailing twelve months is around 4.32%, more than ASEC's 0.46% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
ASEC American Century Securitized Credit ETF | 0.46% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
MBB iShares MBS Bond ETF | 4.32% | 4.21% | 3.94% | 3.40% | 2.31% | 1.05% | 2.10% | 2.77% | 2.64% | 2.23% | 2.58% | 2.66% |
Frequently Asked Questions
MBB and ASEC have a correlation of 0.20, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
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.
MBB is cheaper with a 0.06% expense ratio, compared with 0.29% for ASEC.
MBB has the higher dividend yield at 4.32%, compared with 0.46% for ASEC.
They also come from different issuers: iShares and American Century. Their fees differ too: 0.06% for MBB and 0.29% for ASEC.
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