VBIUX vs. VMBSX
VBIUX (Vanguard Intermediate-Term Bond Index Fund Institutional Plus) and VMBSX (Vanguard Mortgage-Backed Securities Index Fund Admiral Shares) are both Total Bond Market funds from Vanguard. Over the past 10 years, VBIUX returned 1.89%/yr vs 1.87%/yr for VMBSX. Their correlation of 0.84 suggests significant overlap in exposure. VBIUX charges 0.04%/yr vs 0.07%/yr for VMBSX.
Performance
VBIUX vs. VMBSX - Performance Comparison
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Returns By Period
In the year-to-date period, VBIUX achieves a -0.04% return, which is significantly lower than VMBSX's 0.81% return. Both investments have delivered pretty close results over the past 10 years, with VBIUX having a 1.89% annualized return and VMBSX not far behind at 1.87%.
VBIUX
- 1D
- 0.00%
- 1M
- 0.37%
- YTD
- -0.04%
- 6M
- -0.25%
- 1Y
- 5.09%
- 3Y*
- 4.29%
- 5Y*
- 0.29%
- 10Y*
- 1.89%
VMBSX
- 1D
- 0.00%
- 1M
- 0.46%
- YTD
- 0.81%
- 6M
- 0.99%
- 1Y
- 6.98%
- 3Y*
- 4.69%
- 5Y*
- 0.55%
- 10Y*
- 1.87%
VBIUX vs. VMBSX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
VBIUX Vanguard Intermediate-Term Bond Index Fund Institutional Plus | -0.04% | 8.60% | 1.56% | 5.53% | -13.24% | -2.64% | 9.83% | 10.23% | -0.13% | 3.90% |
VMBSX Vanguard Mortgage-Backed Securities Index Fund Admiral Shares | 0.81% | 8.43% | 1.76% | 4.99% | -11.56% | -1.35% | 3.74% | 11.47% | 0.87% | 2.32% |
Correlation
The correlation between VBIUX and VMBSX is 0.91, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.91 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.93 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.92 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.86 |
Correlation (All Time) Calculated using the full available price history since Sep 28, 2011 | 0.84 |
The correlation between VBIUX and VMBSX has been stable across timeframes, ranging from 0.84 to 0.93 - a consistent structural relationship.
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Return for Risk
VBIUX vs. VMBSX — Risk / Return Rank
VBIUX
VMBSX
VBIUX vs. VMBSX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for Vanguard Intermediate-Term Bond Index Fund Institutional Plus (VBIUX) and Vanguard Mortgage-Backed Securities Index Fund Admiral Shares (VMBSX). 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.
| VBIUX | VMBSX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.60 | ||
| Sortino ratioReturn per unit of downside risk | -0.89 | ||
| Omega ratioGain probability vs. loss probability | 1.22 | 1.34 | -0.12 |
| Calmar ratioReturn relative to maximum drawdown | 1.54 | 2.63 | -1.09 |
| Martin ratioReturn relative to average drawdown | 4.54 | 8.86 | -4.32 |
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
| VBIUX | VMBSX | Difference | |
|---|---|---|---|
Sharpe Ratio (1Y)Calculated over the trailing 1-year period | 1.24 | 1.84 | -0.60 |
Sharpe Ratio (5Y)Calculated over the trailing 5-year period | 0.05 | 0.09 | -0.04 |
Sharpe Ratio (10Y)Calculated over the trailing 10-year period | 0.35 | 0.39 | -0.03 |
Sharpe Ratio (All Time)Calculated using the full available price history | 0.47 | 0.59 | -0.12 |
Drawdowns
VBIUX vs. VMBSX - Drawdown Comparison
The maximum VBIUX drawdown since its inception was -19.18%, which is greater than VMBSX's maximum drawdown of -17.44%. Use the drawdown chart below to compare losses from any high point for VBIUX and VMBSX.
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Drawdown Indicators
| VBIUX | VMBSX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -19.18% | -17.44% | -1.74% |
Max Drawdown (1Y)Largest decline over 1 year | -3.33% | -2.67% | -0.66% |
Max Drawdown (3Y)Largest decline over 3 years | -6.05% | -7.53% | +1.48% |
Max Drawdown (5Y)Largest decline over 5 years | -18.83% | -17.12% | -1.71% |
Max Drawdown (10Y)Largest decline over 10 years | -19.18% | -17.44% | -1.74% |
Current DrawdownCurrent decline from peak | -1.83% | -1.22% | -0.61% |
Average DrawdownAverage peak-to-trough decline | -4.09% | -2.48% | -1.61% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.12% | 0.79% | +0.33% |
Volatility
VBIUX vs. VMBSX - Volatility Comparison
The current volatility for Vanguard Intermediate-Term Bond Index Fund Institutional Plus (VBIUX) is 1.37%, while Vanguard Mortgage-Backed Securities Index Fund Admiral Shares (VMBSX) has a volatility of 1.46%. This indicates that VBIUX experiences smaller price fluctuations and is considered to be less risky than VMBSX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| VBIUX | VMBSX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.37% | 1.46% | -0.09% |
Volatility (6M)Calculated over the trailing 6-month period | 2.98% | 2.73% | +0.25% |
Volatility (1Y)Calculated over the trailing 1-year period | 4.15% | 3.82% | +0.33% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.39% | 6.40% | -0.01% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.38% | 4.86% | +0.52% |
VBIUX vs. VMBSX - Expense Ratio Comparison
VBIUX has a 0.04% expense ratio, which is lower than VMBSX's 0.07% 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
VBIUX vs. VMBSX - Dividend Comparison
VBIUX's dividend yield for the trailing twelve months is around 4.24%, more than VMBSX's 4.16% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
VBIUX Vanguard Intermediate-Term Bond Index Fund Institutional Plus | 4.24% | 4.04% | 3.82% | 2.59% | 2.42% | 3.08% | 2.95% | 2.76% | 2.89% | 2.77% | 3.09% | 3.14% |
VMBSX Vanguard Mortgage-Backed Securities Index Fund Admiral Shares | 4.16% | 4.18% | 4.24% | 3.28% | 2.31% | 0.99% | 2.00% | 7.48% | 2.72% | 2.16% | 1.98% | 2.01% |
Frequently Asked Questions
With a correlation of 0.91, VBIUX and VMBSX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.
VMBSX has higher volatility (1.46%) compared to VBIUX (1.37%). In terms of maximum drawdown, VBIUX dropped -19.18% vs VMBSX's -17.44%.
VMBSX currently has the higher Sharpe Ratio (1.84 vs 1.24), 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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