VUSFX vs. VMBIX
VUSFX (Vanguard Ultra-Short-Term Bond Fund Admiral Shares) and VMBIX (Vanguard Mortgage-Backed Securities Index Fund Institutional Shares) are both Total Bond Market funds from Vanguard. Over the past 10 years, VUSFX returned 2.71%/yr vs 1.41%/yr for VMBIX. At a 0.50 correlation, their price movements are largely independent. VUSFX charges 0.10%/yr vs 0.05%/yr for VMBIX.
Performance
VUSFX vs. VMBIX - Performance Comparison
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Returns By Period
In the year-to-date period, VUSFX achieves a 1.42% return, which is significantly higher than VMBIX's 0.86% return. Over the past 10 years, VUSFX has outperformed VMBIX with an annualized return of 2.71%, while VMBIX has yielded a comparatively lower 1.41% annualized return.
VUSFX
- 1D
- 0.00%
- 1M
- 0.36%
- YTD
- 1.42%
- 6M
- 1.76%
- 1Y
- 4.51%
- 3Y*
- 5.44%
- 5Y*
- 3.50%
- 10Y*
- 2.71%
VMBIX
- 1D
- 0.04%
- 1M
- 0.47%
- YTD
- 0.86%
- 6M
- 1.01%
- 1Y
- 7.00%
- 3Y*
- 4.71%
- 5Y*
- 0.57%
- 10Y*
- 1.41%
VUSFX vs. VMBIX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
VUSFX Vanguard Ultra-Short-Term Bond Fund Admiral Shares | 1.42% | 5.11% | 6.11% | 5.53% | -0.38% | 0.08% | 2.10% | 3.39% | 2.10% | 1.37% |
VMBIX Vanguard Mortgage-Backed Securities Index Fund Institutional Shares | 0.86% | 8.44% | 1.78% | 4.97% | -11.56% | -1.30% | 3.77% | 6.19% | 0.88% | 2.38% |
Correlation
The correlation between VUSFX and VMBIX is 0.56, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.56 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.61 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.64 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.50 |
Correlation (All Time) Calculated using the full available price history since Jan 5, 2016 | 0.50 |
The correlation between VUSFX and VMBIX shifts across timeframes, from 0.50 (all time) to 0.64 (5 years), reflecting how their relationship changes across market environments.
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Return for Risk
VUSFX vs. VMBIX — Risk / Return Rank
VUSFX
VMBIX
VUSFX vs. VMBIX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for Vanguard Ultra-Short-Term Bond Fund Admiral Shares (VUSFX) and Vanguard Mortgage-Backed Securities Index Fund Institutional Shares (VMBIX). 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.
| VUSFX | VMBIX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | +5.83 | ||
| Sortino ratioReturn per unit of downside risk | +12.60 | ||
| Omega ratioGain probability vs. loss probability | 4.69 | 1.34 | +3.35 |
| Calmar ratioReturn relative to maximum drawdown | 18.20 | 2.67 | +15.53 |
| Martin ratioReturn relative to average drawdown | 108.57 | 9.15 | +99.42 |
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month. | |||
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Sharpe Ratios by Period
| VUSFX | VMBIX | Difference | |
|---|---|---|---|
Sharpe Ratio (1Y)Calculated over the trailing 1-year period | 7.69 | 1.86 | +5.83 |
Sharpe Ratio (5Y)Calculated over the trailing 5-year period | 4.35 | 0.09 | +4.26 |
Sharpe Ratio (10Y)Calculated over the trailing 10-year period | 4.00 | 0.29 | +3.71 |
Sharpe Ratio (All Time)Calculated using the full available price history | 4.00 | 0.51 | +3.49 |
Drawdowns
VUSFX vs. VMBIX - Drawdown Comparison
The maximum VUSFX drawdown since its inception was -1.71%, smaller than the maximum VMBIX drawdown of -17.44%. Use the drawdown chart below to compare losses from any high point for VUSFX and VMBIX.
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Drawdown Indicators
| VUSFX | VMBIX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -1.71% | -17.44% | +15.73% |
Max Drawdown (1Y)Largest decline over 1 year | -0.25% | -2.63% | +2.38% |
Max Drawdown (3Y)Largest decline over 3 years | -0.35% | -7.51% | +7.16% |
Max Drawdown (5Y)Largest decline over 5 years | -1.71% | -17.11% | +15.40% |
Max Drawdown (10Y)Largest decline over 10 years | -1.71% | -17.44% | +15.73% |
Current DrawdownCurrent decline from peak | 0.00% | -1.15% | +1.15% |
Average DrawdownAverage peak-to-trough decline | -0.15% | -2.51% | +2.36% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.04% | 0.77% | -0.73% |
Volatility
VUSFX vs. VMBIX - Volatility Comparison
The current volatility for Vanguard Ultra-Short-Term Bond Fund Admiral Shares (VUSFX) is 0.13%, while Vanguard Mortgage-Backed Securities Index Fund Institutional Shares (VMBIX) has a volatility of 1.47%. This indicates that VUSFX experiences smaller price fluctuations and is considered to be less risky than VMBIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| VUSFX | VMBIX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 0.13% | 1.47% | -1.34% |
Volatility (6M)Calculated over the trailing 6-month period | 0.41% | 2.77% | -2.36% |
Volatility (1Y)Calculated over the trailing 1-year period | 0.59% | 3.80% | -3.21% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 0.81% | 6.37% | -5.56% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 0.68% | 4.79% | -4.11% |
VUSFX vs. VMBIX - Expense Ratio Comparison
VUSFX has a 0.10% expense ratio, which is higher than VMBIX's 0.05% 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
VUSFX vs. VMBIX - Dividend Comparison
VUSFX's dividend yield for the trailing twelve months is around 4.53%, more than VMBIX's 4.18% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
VMBIX Vanguard Mortgage-Backed Securities Index Fund Institutional Shares | 4.18% | 4.20% | 4.27% | 3.29% | 2.33% | 1.01% | 2.02% | 2.76% | 2.74% | 2.18% | 2.13% | 2.04% |
VUSFX Vanguard Ultra-Short-Term Bond Fund Admiral Shares | 4.53% | 4.73% | 5.52% | 4.15% | 1.38% | 0.53% | 1.62% | 2.68% | 2.23% | 1.52% | 1.07% | 0.00% |
Frequently Asked Questions
VUSFX and VMBIX have a correlation of 0.56, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
VMBIX has higher volatility (1.47%) compared to VUSFX (0.13%). In terms of maximum drawdown, VUSFX dropped -1.71% vs VMBIX's -17.44%.
VUSFX currently has the higher Sharpe Ratio (7.69 vs 1.86), 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.
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