MBB vs. BIL
MBB (iShares MBS Bond ETF) and BIL (SPDR Bloomberg 1-3 Month T-Bill ETF) are both exchange-traded funds - MBB is a Mortgage Backed Securities fund tracking the Barclays Capital U.S. MBS Index, while BIL is a Government Bonds fund tracking the Bloomberg 1-3 Month U.S. Treasury Bill Index. Both are passively managed. Over the past 10 years, MBB returned 1.33%/yr vs 2.19%/yr for BIL. At a 0.04 correlation, their price movements are largely independent. MBB charges 0.06%/yr vs 0.14%/yr for BIL.
Performance
MBB vs. BIL - Performance Comparison
Loading charts...
Returns By Period
In the year-to-date period, MBB achieves a 1.01% return, which is significantly lower than BIL's 1.56% return. Over the past 10 years, MBB has underperformed BIL with an annualized return of 1.33%, while BIL has yielded a comparatively higher 2.19% annualized return.
MBB
- 1D
- 0.65%
- 1M
- 0.67%
- YTD
- 1.01%
- 6M
- 1.29%
- 1Y
- 6.49%
- 3Y*
- 4.43%
- 5Y*
- 0.41%
- 10Y*
- 1.33%
BIL
- 1D
- 0.01%
- 1M
- 0.28%
- YTD
- 1.56%
- 6M
- 1.77%
- 1Y
- 3.87%
- 3Y*
- 4.63%
- 5Y*
- 3.43%
- 10Y*
- 2.19%
MBB vs. BIL - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
MBB iShares MBS Bond ETF | 1.01% | 8.38% | 1.31% | 5.01% | -11.74% | -1.43% | 4.08% | 6.18% | 0.82% | 2.49% |
BIL SPDR Bloomberg 1-3 Month T-Bill ETF | 1.56% | 4.15% | 5.19% | 4.94% | 1.40% | -0.10% | 0.40% | 2.03% | 1.74% | 0.69% |
Correlation
The correlation between MBB and BIL is -0.14, meaning they tend to move in opposite directions. This is especially valuable for risk management - when one declines, the other has historically tended to hold steady or rise.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | -0.14 |
Correlation (3Y) Calculated over the trailing 3-year period | -0.04 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.04 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.05 |
Correlation (All Time) Calculated using the full available price history since May 30, 2007 | 0.04 |
The correlation between MBB and BIL shifts across timeframes, from -0.14 (1 year) to 0.05 (10 years), reflecting how their relationship changes across market environments.
Compare stocks, funds, or ETFs
Search for stocks, ETFs, and funds for a quick comparison or use the comparison tool for more options.
Return for Risk
MBB vs. BIL — Risk / Return Rank
MBB
BIL
MBB vs. BIL - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares MBS Bond ETF (MBB) and SPDR Bloomberg 1-3 Month T-Bill ETF (BIL). 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 | BIL | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -18.13 | ||
| Sortino ratioReturn per unit of downside risk | -172.01 | ||
| Omega ratioGain probability vs. loss probability | 1.26 | 87.91 | -86.65 |
| Calmar ratioReturn relative to maximum drawdown | 2.21 | 355.36 | -353.15 |
| Martin ratioReturn relative to average drawdown | 7.06 | 2,817.81 | -2,810.74 |
Loading charts...
Drawdowns
MBB vs. BIL - Drawdown Comparison
The maximum MBB drawdown since its inception was -17.64%, which is greater than BIL's maximum drawdown of -0.78%. Use the drawdown chart below to compare losses from any high point for MBB and BIL.
Loading charts...
Drawdown Indicators
| MBB | BIL | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -17.64% | -0.78% | -16.86% |
Max Drawdown (1Y)Largest decline over 1 year | -2.94% | -0.01% | -2.93% |
Max Drawdown (3Y)Largest decline over 3 years | -7.68% | -0.01% | -7.67% |
Max Drawdown (5Y)Largest decline over 5 years | -17.19% | -0.09% | -17.10% |
Max Drawdown (10Y)Largest decline over 10 years | -17.64% | -0.21% | -17.43% |
Current DrawdownCurrent decline from peak | -1.09% | 0.00% | -1.09% |
Average DrawdownAverage peak-to-trough decline | -2.35% | -0.26% | -2.09% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.92% | 0.00% | +0.92% |
Volatility
MBB vs. BIL - Volatility Comparison
iShares MBS Bond ETF (MBB) has a higher volatility of 1.57% compared to SPDR Bloomberg 1-3 Month T-Bill ETF (BIL) at 0.06%. This indicates that MBB's price experiences larger fluctuations and is considered to be riskier than BIL based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
Loading charts...
Volatility by Period
| MBB | BIL | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.57% | 0.06% | +1.51% |
Volatility (6M)Calculated over the trailing 6-month period | 3.31% | 0.14% | +3.17% |
Volatility (1Y)Calculated over the trailing 1-year period | 4.47% | 0.20% | +4.27% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.82% | 0.26% | +6.56% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.31% | 0.26% | +5.05% |
MBB vs. BIL - Expense Ratio Comparison
MBB has a 0.06% expense ratio, which is lower than BIL's 0.14% 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
MBB vs. BIL - Dividend Comparison
MBB's dividend yield for the trailing twelve months is around 4.26%, more than BIL's 3.86% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
BIL SPDR Bloomberg 1-3 Month T-Bill ETF | 3.86% | 4.13% | 5.03% | 4.92% | 1.35% | 0.00% | 0.30% | 2.05% | 1.66% | 0.68% | 0.07% | 0.00% |
MBB iShares MBS Bond ETF | 4.26% | 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 BIL have a correlation of -0.14, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
MBB has higher volatility (1.57%) compared to BIL (0.06%). In terms of maximum drawdown, MBB dropped -17.64% vs BIL's -0.78%.
On 10-year performance, BIL leads with 2.19% vs 1.33% for MBB. On fees, MBB is cheaper at 0.06% per year. On volatility, BIL has been the lower-risk option at 0.06%. The better choice depends on whether you care most about return, fees, risk, or income.
Over the 10-year period, BIL has performed better with a 2.19% return vs 1.33%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.
MBB is cheaper with a 0.06% expense ratio, compared with 0.14% for BIL.
MBB has the higher dividend yield at 4.26%, compared with 3.86% for BIL.
MBB is categorized as Mortgage Backed Securities, while BIL is Government Bonds. MBB tracks Barclays Capital U.S. MBS Index, while BIL tracks Bloomberg 1-3 Month U.S. Treasury Bill Index. They also come from different issuers: iShares and State Street. Their fees differ too: 0.06% for MBB and 0.14% for BIL.
BIL currently has the higher Sharpe Ratio (19.59 vs 1.46), 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.
Find the right allocation for MBB and BIL
Add both to a portfolio and optimize allocations for your target — whether that's maximizing returns, minimizing drawdowns, or balancing risk across holdings.
Open Portfolio Optimizer