BIL vs. MBB
BIL (SPDR Bloomberg 1-3 Month T-Bill ETF) and MBB (iShares MBS Bond ETF) are both exchange-traded funds - BIL is a Government Bonds fund tracking the Bloomberg 1-3 Month U.S. Treasury Bill Index, while MBB is a Mortgage Backed Securities fund tracking the Barclays Capital U.S. MBS Index. Both are passively managed. Over the past 10 years, BIL returned 2.19%/yr vs 1.33%/yr for MBB. At a 0.04 correlation, their price movements are largely independent. BIL charges 0.14%/yr vs 0.06%/yr for MBB.
Performance
BIL vs. MBB - Performance Comparison
Loading charts...
Returns By Period
In the year-to-date period, BIL achieves a 1.56% return, which is significantly higher than MBB's 1.01% return. Over the past 10 years, BIL has outperformed MBB with an annualized return of 2.19%, while MBB has yielded a comparatively lower 1.33% annualized return.
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
- 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 vs. MBB - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
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% |
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% |
Correlation
The correlation between BIL and MBB 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 BIL and MBB 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
BIL vs. MBB — Risk / Return Rank
BIL
MBB
BIL vs. MBB - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for SPDR Bloomberg 1-3 Month T-Bill ETF (BIL) 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.
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.
| BIL | MBB | 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 | 87.91 | 1.26 | +86.65 |
| Calmar ratioReturn relative to maximum drawdown | 355.36 | 2.21 | +353.15 |
| Martin ratioReturn relative to average drawdown | 2,817.81 | 7.06 | +2,810.74 |
Loading charts...
Drawdowns
BIL vs. MBB - Drawdown Comparison
The maximum BIL drawdown since its inception was -0.78%, smaller than the maximum MBB drawdown of -17.64%. Use the drawdown chart below to compare losses from any high point for BIL and MBB.
Loading charts...
Drawdown Indicators
| BIL | MBB | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -0.78% | -17.64% | +16.86% |
Max Drawdown (1Y)Largest decline over 1 year | -0.01% | -2.94% | +2.93% |
Max Drawdown (3Y)Largest decline over 3 years | -0.01% | -7.68% | +7.67% |
Max Drawdown (5Y)Largest decline over 5 years | -0.09% | -17.19% | +17.10% |
Max Drawdown (10Y)Largest decline over 10 years | -0.21% | -17.64% | +17.43% |
Current DrawdownCurrent decline from peak | 0.00% | -1.09% | +1.09% |
Average DrawdownAverage peak-to-trough decline | -0.26% | -2.35% | +2.09% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.00% | 0.92% | -0.92% |
Volatility
BIL vs. MBB - Volatility Comparison
The current volatility for SPDR Bloomberg 1-3 Month T-Bill ETF (BIL) is 0.06%, while iShares MBS Bond ETF (MBB) has a volatility of 1.57%. This indicates that BIL experiences smaller price fluctuations and is considered to be less risky than MBB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
Loading charts...
Volatility by Period
| BIL | MBB | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 0.06% | 1.57% | -1.51% |
Volatility (6M)Calculated over the trailing 6-month period | 0.14% | 3.31% | -3.17% |
Volatility (1Y)Calculated over the trailing 1-year period | 0.20% | 4.47% | -4.27% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 0.26% | 6.82% | -6.56% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 0.26% | 5.31% | -5.05% |
BIL vs. MBB - Expense Ratio Comparison
BIL has a 0.14% 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
BIL vs. MBB - Dividend Comparison
BIL's dividend yield for the trailing twelve months is around 3.86%, less than MBB's 4.26% 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
BIL and MBB 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, BIL dropped -0.78% vs MBB's -17.64%.
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.
BIL is categorized as Government Bonds, while MBB is Mortgage Backed Securities. BIL tracks Bloomberg 1-3 Month U.S. Treasury Bill Index, while MBB tracks Barclays Capital U.S. MBS Index. They also come from different issuers: State Street and iShares. Their fees differ too: 0.14% for BIL and 0.06% for MBB.
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 BIL and MBB
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